What Is Software Testing? Definition, Basics, Importance, Types & Method

Software Testing

Software Testing is the highly crucial final lap of the journey that had an amazing start from Software Development. Behind developing every tech product, the primary objective is to solve a truly important problem and build a sustainable, profit-making business from it.

But, what if the product breaks or crashes your entire set of products? It's terrible to imagine, right? That's why technology companies set and maintain a significant priority level to test each and every product before launching them.

With that, we have come to the deciding point for the topic of today's discussion i.e. Software Testing.

What Is Software Testing?

Software Testing is the process of checking a software product for errors and making sure that it qualifies in matching the expectations/planning made for it.

In this process, each and every functionality such as security, reliability, performance, and all other aspects of a software product is passed through numerous test cases by the use of manual or automated software testing tools.

Those test cases decide whether the product has any defect or not. Then the product is improved to assure that it provides the best quality in every bit of it. That's why Software Testing is also called Quality Assurance.

The Importance of Software Testing

Well, software testing holds the same importance as software development. Some organizations even consider it more important than any other step in the software journey. And, it is logically true.

There is no point in continuing to develop awesome software products if they cannot maintain a good performance and quality. People often like using the products that provide them with consistently good performance rather than those that come with numerous functionalities but fail to perform.

Hence, you can clearly see what an immense importance software testing has. Check out the following information to know what disasters were previously caused by broken software products.

The Mariner 1 Spacecraft, 1962:

Fatal accidents due to minor bugs in the software is a common problem for so long that long back in 1962, the world experienced a costly accident due to a petty bug in a software.

The Mariner 1 Spacecraft was being sent by NASA to flypast Venus as a part of a unmanned data-gathering space mission. Immediately after it was launched from Cape Canaveral, the rocket looked like it was receiving the wrong signal about the route.

Out of fear that it could crashland on earth, it was destroyed by a self-destruction order from the NASA engineers.

Later in the investigation, it was found that a missing hyphen in a line of code caused the massive failure that cost over $18 million at that time (about $169 million in today's valuation).

The Morris Worm, 1988:

Well, this is somehow the first-ever infectious computer virus. In 1988, Robert Tappan Morris, a student from Cornell University created this worm as part of an experience.

But, unfortunately, then it could not be controlled and spread like wildfire causing tens of thousands of computers to face a coding error, and eventually, they crashed.

The computers were connected through a very early version of the internet and as a result, the morris worm could not be resisted from spreading. The losses cost somewhat about a whopping $10 million but the student was penalized with charges of criminal hacking and a fine of $10000.

However, as this action of that student exposed a great vulnerability in digital security and triggered the world to improve the protective measures, he was credited for his innovation and not treated as a criminal.

The source code of that old, infectious virus is kept as a museum piece on a floppy disc at the University of Boston. However, this incident can clearly be concluded as the result of not testing the security measures against different complex problems.

Airbus A300 Crash, 1994:

Software bugs have also become directly fatal for human lives. On April 26, 1994, China Airlines Airbus A300 crashed due to a software bug and all 264 people on board lost their lives.

Therac-25 Malfunction, 1985:

In 1985, a software bug caused Canada's Therac-25 radiation therapy machine to malfunction and it delivered lethal radiation doses to patients. It caused the death of 3 patients and left 3 others critically injured.

Military Satellite Launch Failure, 1999:

In 1999, a $1.2 billion military satellite launch failed due to a software bug. This is the costliest accident caused by a software bug.

The Big Billion Day Failure, 2014:

Even the advanced technology of modern times could not always defend against major mishaps due to software bugs. In 2014, Flipkart, a huge Indian e-commerce company, launched a massive offer named “The Big Billion Sale” but, they hadn't tested if their website was capable of handling such huge traffic.

As a result, when unexpectedly huge traffic came to their website, it started malfunctioning. It was having long downtime, orders were getting canceled and eventually, all these caused a deeply negative impact on the company's reputation.

Bloomberg Financial Market Crash, 2015:

In April 2015, a software glitch caused a huge system crash in Bloomberg terminal in London and more than 300000 traders in Financial Markets got affected. Due to this, the government had to postpone a 3 billion pound debt sale.

Royal Bank Crash, 2015:

  • In 2015, a software bug caused the failure of about 600000 payments in the Royal Bank of Scotland and the bank was fined 66 million pounds.

There are several more terrible incidents that are caused by small bugs in the software but, the above-mentioned ones are good enough to make the world understand how important it is to test every tiny bit of a tech product before launching it.

For better understanding, let's take a look at the further discussion on software testing.

The Benefits of Software Testing

Till now, you have seen what kind of mishaps occurred due to a lack of software testing. But, without an in-depth idea about how software testing can save you from such situations, no one will understand its true importance.

So, check out the following benefits of testing every bit of a tech product before making it available for everyone.

Significantly Improves Product Quality

Any business becomes successful when its customers recognize it for its product quality and business ethics.

A good product quality that is maintained with continuous improvement works for a remarkable positive impression of your business.

And, that can only be achieved when every smaller than the smallest feature of your product works perfectly.

Hence, every company that is willing to have a consistently good performing business, must set a really high priority to test its products and focus on improving their quality. They must follow the concept that software testing or an efficient QA practice is one of the most crucial steps in maintaining a high-performing business.

Enhances Security

As modern tech tools deal with large sets of data, it becomes more crucial to keep those data protected. Various complex software products often require huge sets of your personal information to achieve the highest performance of their features.

And, every renowned company always makes sure that hackers do not reach those data and the well-secure products work for building and maintaining a positive impression about the company.

For example, social media apps need access to your storage and camera for posting content. Banking and e-commerce applications operate on confidential payment information.

Other than these, there are numerous applications that we regularly use and you must have noticed that those applications ask for several permissions to use the sensors & components of your devices and gather data through them.

Also, wrong hands getting access to your data is not the only concern that makes everyone brainstorm about the overall security system. Sometimes the failure of any cloud storage service or similar products can result in the loss of the data that is very precious to you.

Imagine that you have stored your valuable data in Google Drive or iCloud, and a small software bug demolished all your data without leaving any scope to retrieve them. Seems like a nightmare, right?

Well, compromising on proper testing of such software products can surely turn that nightmare into reality. Hence, every organization that is concerned about the security of their users' information, must make proper use of their planning, time, and resources to test their products.

Saves Your Resources and Lets You Provide Cost-effective Services

If any bug is detected during the earlier stages of developing and launching a product, it becomes easier to get rid of it and the product owner can save a lot of time and resources in the long run.

That's why every well-organized IT company focuses on testing their products thoroughly before launching them and eventually supports their business by saving a lot of time and resources that would otherwise get wasted in software debugging.

Also, saving those resources and maintaining a good budget for developing a product helps the companies provide cost-effective services to their customers. Hence, thorough testing of software products creates a win-win situation for both the seller and the customer.

Helps In Detection of Compatibility with Different Devices and Platforms

Those times no longer exist when very few people had computers or any kind of electronic gadgets and most of those devices were similar.

Nowadays, every moment several electronic gadgets are being launched and everyone is choosing the most suitable ones for them.

That means there are numerous types of gadgets operating in the market and their respective users are always on the search for the best performing applications for their products.

Now, it is a fact that different tech products have different compatibility with different devices. For example, a website or web app that is performing well on a desktop may not perform at all on mobiles.

Also, any specific web product may perform differently on different mobile devices. That explains why it is so crucial to test every web product on different devices with different screen resolutions.

For browser-based applications, testing on different browsers is essential. Nowadays, there are plenty of browser options available that enable everyone to choose the best-suited one according to their needs.

Any application may run smoothly on Google Chrome but its performance can deteriorate on Mozilla Firefox, Safari, or Internet Explorer. This enhances the importance of cross-browser testing for every smaller than the smallest web product to become sure of its compatibility with each browser.

Ensures Customer Satisfaction

One of the prime objectives of any business is to provide the best of everything to their customers. And, it is always possible that the designs that you have prepared with extreme dedication, may not be very preferred by your customers.

Developing a widely loved UI & UX design takes a lot of research, planning, and testing. That's why UI & UX testing before launching a product into the market is an extremely important step that can be highly beneficial for your business.

Your customers will eventually get to use the most suitable products and you will acquire a satisfied customer base.

Types of Software Testing

You have already got the idea that software testing is a huge domain. Hence, naturally, it is expected to have a massive classification. As the testing process involves a lot of aspects, it can be classified based on various criteria.

Though the tests can be broadly classified into the two categories i.e. manual testing and automated testing, they are also differentiated based on whether they involve coding or are codeless.

However, many efficient testing methods consist of hybrid approaches i.e. the mix of both coding and no-code testing methods.

For an easier classification, tests are categorized according to the group of tests included in any particular type of testing and based on how much the tests know about the internal implementation of the system under test. So, the prime categories of software testing are as follows -

Manual Testing

Though this era is mostly all about automation, till now, the traditional methods of testing used to involve the participation of QA engineers to test everything by themselves. And, still, there are a few tests that are mainly executed manually.

Manual testing often becomes very time-consuming and cumbersome as the QA engineers have to take care of testing every bit of the tech products under testing by themselves.

But, the attention to detail and testing everything minutely from the end user's perspective make the QA engineers stay on the correct path towards growth.

As the efficiency and usefulness of the test scripts depend on the expertise and accuracy of the QA engineers, they are always trained to follow high-level guides and analyze if the scripts are running perfectly and producing expected results.

But, no QA engineer should worry about the complex processes. Any reputed manual testing tool can easily help the QA engineers out in any situation.

Automated Testing

In simple words, the process of executing the steps of software testing through efficient automation methods is called Automated Testing. In this process, testers use automated testing tools to execute the test steps and generate the test results automatically.

Though Selenium is one of the most popular names among automated testing tools, Preflight exceeds it in every aspect of a simple yet effective no-code testing tool. It provides amazing performance in all its awesome features like auto-recording & playback of set tests, generating random emails & other variables, providing the opportunity to add custom codes, setting text & visual assertions, and an amazing user-friendly interface allowing any non-technical user to easily navigate through every functionality, etc.

Hence, if you are willing to get the best no-code testing experience, Preflight is the right choice for you.

Functional Testing

As the name suggests, Functional Testing is all about testing the functions of a software. Your software may have numerous functionalities but, they cannot perform the same under different conditions.

That's why it's essential to test each and every functionality of your software under various test conditions. Efficient test automation tools like Preflight provide diverse forms of inputs to the software functionalities and verify if the outputs are matching the expected ones or not.

The prime priority in this type of testing is checking the behavior of the software and its functionalities. Testers or testing tools provide more attention to testing it for different inputs rather than bothering much about its source code.

Based on several criteria, Functional Testing is categorized as the following -

Unit Testing:

A unit represents every smallest testable component of the software. It is evident that for the overall perfect operation of software, each of its components must work properly. Unit testing or Component testing ensures that every smaller than the smallest individual module of the source code is working absolutely fine.

Integration Testing:

The operation of any software involves a lot of interdependence or connectivity among different internal modules. And, the best performance from the software cannot afford any issue in the data transfer among those modules. And, there comes the involvement of Integration testing.

The main objective of Integration Testing or String Testing is to ensure that the interdependence among the internal modules is performing fine. The strategy behind this type of testing is mainly divided into 3 types i.e. the Top-Down Approach, the Bottom-Up Approach, and the Sandwich Approach (combination of the Top-Down and Bottom-Up approaches). To know more about Integration Testing, check out our article on the Testing Pyramid.

System Testing:

This type of testing is also called End-to-end testing because it intends to ensure that the complete software and its specifications are performing properly. It checks if, for every specific input, the software is producing the expected output. In other words, you can say that system testing checks if the users will receive the expected results or experience from the software.

Acceptance Testing:

No matter how much the product team tests the software, the users will always use it from a different perspective. So, it is quite essential to check if the users are getting benefited from the software and actually accepting it.

Hence, in the acceptance testing stage, the target users of the software use it and report if they experience any bugs. Different types of acceptance testing are Alpha, Beta, and Gamma testing.

Sanity Testing:

The tests that check the logical reasoning behind the working of the software, are included in the Sanity testing category.

Smoke Testing:

The simple and basic functionalities of any software is really crucial in the completion of its performance. And, it's the responsibility of the smoke tests to ensure that those functionalities work perfectly.

Interface Testing:

The objective of Interface testing is to check if the communication between two software systems is performing as they are supposed to.

Regression Testing:

  • It is indeed one of the most crucial test types. These tests are such types of tests that are repeated every time a feature is added. Hence, companies spend a lot of time, effort, and resources on this type of testing to receive the best results. You must have a detailed idea about it and for that, you must check out our article on Regression testing.

Non-Functional Testing

While Functional testing looks at the ways to attract users, Non-Functional testing is more concerned about impressing them and acquiring a satisfied customer base. Based on its focus on performance, Non-Functional testing can be categorized as follows -

Performance Testing:

Imagine that you are using a software that has a lot of features but, whenever you click on anything, it keeps loading for some moments. Being a user who has a lot of better options available, will you prefer such laggy software?

Certainly not. And, that's how software loses its reliability and eventually, the business fails in holding a satisfied customer base.

Performance testing is all about ensuring that software is performing with efficiency and speed equal to or better than what is expected from it. It checks software under various levels of difficulty and workload. So, you can surely consider performance testing as one of the topmost priorities while testing your software.

Endurance Testing:

Though we just saw that performance testing is the one concerned about how the software will perform under different conditions, there are some specific types of tests that focus on different aspects of a practical condition.

Endurance testing focuses on checking whether the software can withstand a certain processing load that it is expected to endure for long and its memory consumption is also observed during the endurance testing period.

That observation can provide you with an idea about whether any potential failure may occur in the same or more workload.

Load Testing:

The sole objective of load testing is to test how the application is performing under a huge workload. So, during load testing, the most common scenario that you can expect to see is putting enormous traffic and other loads on your web product and observing the performance of its functionalities.

Stress Testing:

In this type of testing, the software is made to run in conditions beyond its regular capacity and is observed to figure out how much strain/stress it can bear before it fails.

Volume Testing:

Your software is not going to face the same or less amount of data that it is built for handling. That's why it tested against an increased amount of data to ensure its best performance under every condition.

Security Testing:

Security is a huge concern in today's massive cyber world. The number of users is always increasing at a tremendous rate and eventually, businesses are bound to keep their data secure and perform the operations efficiently.

And, that explains the importance of making your software run through robust security testing that proves its capability against internal and external threats.

Compatibility Testing:

The enormous growth in technology has provided the world with various types of technical environments.

That means if you want your tech product to sustain in the market, it must suit a range of technical environments. For example, if you are testing software, make sure that it performs well in different operating systems; for a web application, the test environments become different browsers, and so on.

Install Testing:

If any product supports different technical environments, it must perform perfectly during installation. And, that's what install testing assures.

Recovery Testing:

The objective of recovery testing is to check an application's capability to recover from hardware crashes and failures.

Reliability Testing:

One of the most common purposes behind using a tech product is leaving it with a responsibility to perform a task for a specific period of time. In definitive words, this property is called reliability. Reliability testing is nothing but confirming if any tech product is reliable or not.

Usability Testing:

It checks how much ease an end-user will experience while learning about software, using it, and preparing inputs & outputs.

Compliance Testing:

This type of testing checks the product's compliance with external and internal standards.

Localization Testing:

  • This type of testing is all about checking how your product performs in local environments.

Black-box Testing

It can be described as testing a tech product completely from the users' perspective. In Black-box testing, you have the same amount of information as your customers have.

You will not get the benefit of knowing the product's structure, code, or logic.

Black box testing uses the dynamic testing approach. That means that the product is tested when the code is being executed.

This strategy helps the tester know how the product will behave and how the users will experience it when it will be up and running.

White-box Testing

In contrast with Black-box testing, White-box testing needs the testers to know the most about the product. And, the objective of white-box testing is the objective behind having so much information.

White-box testing is executed to detect inefficiencies in codes, find out poor coding practices such as unnecessary lines of code, etc.

The prime focus of white-box testing is not checking the working of the application. It prioritizes looking at the points to make the application better.

You can make a lot of improvements to your product throughout its entire life cycle, but the best improvements take place while solving any issue noticed in the product.

White-box testing mostly follows a static testing approach. That means in this type of testing, you have to test the code while it is not in the execution stage. Static testing is a common practice during the early stages of a product's journey because it is easy to test a product before its deployment.

Gorilla Testing

It is a type of manual testing that is performed repeatedly. In this type of testing, some modules of software are tested individually with random inputs to ensure that each of them is error-free.

The prime objective of this type of testing is to ensure that the software is functioning properly. Gorilla testing is also known as torture testing, fault tolerance testing, and frustrating testing.

Grey-box Testing

This type of testing lies somewhere in the middle ground between Black-box testing and White-box testing as this testing allows you to have partial information about the product.

And, being in the middle-ground enables you to look at the product from both the user's and the developer's perspectives. For example, if a component of your product has a design that it isn't supposed to have, a user cannot identify it as a bug as he/she may think that it is looking as it is designed. But, you can identify it as a bug.

This is how Grey-box testing enables you to test and debug your product.

Software Testing Process

Now, you have an in-depth idea about the main categories of software testing but, you must know about the strategic approach to proceed with the testing process.

Though we have already discussed it with every minute detail in our “STLC - Software Testing Life Cycle” article, we are jotting down its key structure here.

The prime steps to move through software testing are -


Any complicated process can be completed successfully if it starts with strategic planning that focuses on better efficiency, better results, and great ethics. Similarly, in software testing, planning is the first step where every small to big detail about the product and the requirements of tests is taken into account.

Then the to-do checklist is created according to the priority order. Also, for huge testing teams, the task division is done in this phase.


As now you have set the plan for testing, it's time to prepare the parameters for it. In this preparation phase, you have to prepare the test environment, analyze the product & its features, research & collect suitable test cases, learn the suitable techniques for testing, gather necessary testing tools, and start getting familiar with the testing process.

Doing all these in proper order and with proper dedication will let you prepare yourself for the next crucial steps in the STLC.


The main action stage is here. It's time for you to execute the test cases and make all the planning and preparation worth it.

In this stage, your duties are executing the test cases, collecting the results, comparing the obtained results with expected results, and taking notes of the successful & failed test cases.


This is the last phase or the decision phase of STLC. Here, your task is to document all your findings & observations and submit them to the concerned team for analysis. Failed test cases are the greatest concern here.

You have to keep proper account test runs, outputs, and overall results so that the respective team can decide which points they have to prioritize.

Preflight provides the users with amazing features like auto-recording the test execution and saving screenshots of every step. These features bring great ease to the overall testing process.

Automated Testing Doesn't Suppress Manual Testing. They Go Hand-in-hand

All this discussion made us see all the sides of the two types of testing processes i.e. manual testing and automated testing. As we saw how automated testing brings efficiency, we also saw how manual testing holds great importance. A common question that always remains is whether automated testing can suppress the value and importance of manual testing.

Manual testing requires the involvement of a lot of people. In this type of testing, testers test every feature, every functionality, and every small part of the software by themselves and mostly without using any tools.

Even if any tool is used in manual testing, testers need to set up and execute every step by themselves. Then QA Analysts analyze those test reports by themselves and make decisions about improving the software.

On the other hand, automation testing runs mostly by itself. Here, tests are set once and they will keep getting executed by themselves. Constant participation of testers is not necessary here. Hence, it provides remarkable efficiency in repetitive tests like regression tests, etc.

But, you must know the fact that automated testing can never make manual testing obsolete. Automated testing involves the use of a lot of tools and preset test parameters, and QA engineers are those people who write the scripts working behind those tools and the test parameters are also set by those QA engineers.

Hence, an intelligent combination of manual testing and automated testing is the way to achieve the best results.

Experience The Smoothest Automated Testing With Preflight

Automated testing can perform the best only when the best test automation tool is used. There are several such tools available there but the best one must have an easy interface, allows the users to set up the tests within little time, auto-records & saves the tests, has awesome AI functionalities, provides affordable price plans, has an efficient dashboard, etc.

Preflight is the tool that has the best versions of all the features mentioned above. Once you start using it, there is no way you will be able to compare anything else with it. But, for that, you need to first Book a Demo, Checkout our amazing packages, and start cherishing our awesome tool.

To know more about our test automation tool, our Cypress Test Recorder, and moreover, our business, feel free to check out our website. Also, if you want to read more amazing articles on various interesting topics, please visit our blog page.