What is Software Testing?

In the realm of software development, ensuring the quality and reliability of software products is paramount to delivering value to users. Software testing, a crucial process in the software development lifecycle (SDLC), plays a pivotal role in achieving this objective. By meticulously evaluating and verifying that software meets its intended requirements and functions as expected, testing helps identify and eliminate defects, thereby enhancing the overall quality and user experience. This article delves into the world of software testing, exploring its definition, methodology, and best practices, while also distinguishing it from the closely related process of debugging.

1. What is Software Testing?


Software testing is a crucial part of the software development life cycle (SDLC) that involves evaluating and verifying that a software product or application meets the requirements.

The two major testing methods are Manual Testing and Automation Testing

  • Manual testing is a process where a human tester interacts with the software to verify its functionality and identify defects. It involves executing test cases, observing the software\’s behaviour, and reporting any issues or deviations from expected outcomes.
  • Automation testing utilises software tools to execute test cases automatically. Test scripts are written in programming languages like Java, Python, or JavaScript to automate the repetitive tasks and actions involved in manual testing.

The primary objectives of testing include:

  • Identifying and correcting defects (bugs, errors or glitches) in the software to ensure it functions smoothly as intended.
  • Validating requirements to ensure that the software meets the specified functional and non-functional requirements defined during the design phase.
  • Preventing bugs from reaching production early in the development cycle to save time and resources
  • Improving software quality by ensuring it meets the desired standards and user expectations.

Benefits of Software Testing

  • Reduced development costs: Software testing helps to identify and fix defects early, which can save a significant amount of money in development cost, rather than fixing them after the releasing the software. 
  • Improved software quality: Testing helps to ensure that the software meets its requirements and functions as expected. This leads to higher quality software products that are more reliable and less likely to fail. 
  • Increased user satisfaction: By delivering high-quality software, software testing can help to increase user satisfaction and reduce customer support costs.
  • Reduced risk of failures: Testing process helps to identify and mitigate risks before they can cause problems in production. This can help to prevent costly downtime and data loss.
  • Increased developer productivity: Testing can also help to increase developer productivity by reducing the time spent fixing defects. This frees up developers to focus on new features and improvements.

2. Types of Software Testing

There are many types of testing, but they can be broadly divided into two major categories: functional testing and non-functional testing. These terms encompass a wide range of testing types, each with its own purpose. 

Functional testing is concerned with whether the software meets its functional requirements. This means that the software should do what it is supposed to do, and it should do it correctly. Functional testing can be further divided into several types, including:

  • Unit testing tests individual units of code, such as functions or classes.
  • Integration testing tests how different units of code work together.
  • System testing tests the entire software system as a whole.
  • Acceptance testing is performed by the end users of the software to ensure that it meets their needs.

Non-functional testing is concerned with the quality attributes of the software, such as performance, usability, security, and reliability. Non-functional testing can include several types:

  • Performance testing measures the performance of the software under load.
  • Usability testing evaluates how easy the software is to use.
  • Security testing identifies vulnerabilities in the software that could be exploited by attackers.
  • Reliability testing assesses the reliability of the software to ensure that it can operate consistently over time.

3. Software Testing Life Cycle

Many testing processes follow a model called Software Testing Life Cycle (SLTC), which is a structured approach to testing software that ensures it meets quality standards. It is a series of phases or steps that are followed to plan, design, execute and report on testing activities.

The STLC typically consists of the following phases:

Requirement Analysis

The first step in the STLC is to analyse the software requirements to understand what the software is supposed to do. This phase involves reviewing the software requirements specification (SRS) and other relevant documentation.

Test Planning

Once the the team understood the requirements, the next step is to develop a test plan. The test plan outlines the scope of testing, the types of tests to be performed, the resources required, and the schedule for testing.

Test Case Development

In the test case development phase, test cases are created to test the software against the requirements. Test cases are written in a structured format that includes the test objective, the test steps, the expected results, and the actual results.

Environment Setup

The environment setup phase involves setting up the necessary hardware, software, and data for testing. This may include setting up test servers, test databases, and test environments.

Test Execution

The test execution phase involves executing the test cases and recording the results. This may involve manually testing the software or using automated testing tools.

Defect Reporting

Any defects that are found during testing are reported in a defect tracking system. The defect report includes a description of the defect, the steps to reproduce the defect, and the expected and actual results.

Testing Closure 

Once all defects have been fixed, the testing closure phase involves reviewing the test results and ensuring that the software meets the requirements. A test closure report is then written to document the testing activities and the final status of the software.

The STLC is a flexible framework that can be adaptable to the specific needs of a project. The number and type of phases may vary depending on the complexity of the software and the organisation’s testing methodology.

4. Key Differences Between Testing and Debugging


Firstly, we start with some information about debugging. Debugging is the process of identifying and fixing defects in software. It involves analysing error messages , training code execution and modifying code to correct the underlying cause of the defect. Debugging is typically performed after testing has identified defects and reported them to the development team. Debugging is an iterative process, and it may take several times of identifying, reproducing, analysing, and fixing bugs before a program is finally bug-free.

Here are the steps of debugging

  • Identify the bug
  • Reproduce the bug
  • Analyse the bug
  • Formulate a hypothesis
  • Test your hypothesis
  • Repeat steps 3-5 until finishing bug fixing
  • Document the bug and its fix

Differences between software testing and debugging

  Testing Debugging
Purpose Identify and validate software defects Fix identified software defects
Stage in SDLC Throughout the development cycle After testing has identified defects
Process Follows manual approach or uses automated tools Happens in two ways: Reactive and Proactive techniques
Tools and Techniques Test cases, automated testing tools, static analysis tools Debuggers, code analysis tools, logging mechanism
Scope Entire software product Individual units of code
Outcome High-quality software that meets requirements Detect-free software that function as intended
Errors Get displayed in the process Get deducted and dissolved in the process
Mode of operation Both manual and automated Must always be manual 
Focus Overall functionality and behaviour of the software Specific defects
Responsible role Tester Developers
Subcontracting The testing process can be subcontracted to the outside team as well Debugging can not be subcontracted to an outside team
Documentation Test reports that document the testing activities and results Defect reports that document the defects and their fixes

5. Best Practices for Software Testing 

While testing is an essential part of the software development lifecycle (SDLC), it is often an iterative and challenging process. To optimise the effectiveness of software testing, it is important to follow established best practices and continuously refine the testing process.

Plan the testing process

It is important to have a plan for the testing process. This plan should specify the scope of testing, the types of tests, the resources required, and the schedule for testing.

Define clear testing goals

Set clear goals for your testing. What are you trying to achieve with the testing? Are you trying to identify bugs, improve the quality of the software, or ensure that it meets the requirements? Having clear goals will help you to focus your testing efforts and measure your success.

Select the right testing tools

Choose the right testing tools that align with the complexity, goals, and budget of your project. There are a wide range of testing tools available, including automated testing tools, static analysis tools, and manual testing tools.

Design effective test cases

Design comprehensive test cases that cover different scenarios and functionalities of the software. Ensure that the test cases are clear, concise, and easy to execute.

Automate repetitive tasks

Automate repetitive tasks like regression testing and data-driven testing to save time, improve efficiency, and reduce human error.

Perform both manual and automated testing

Combine manual and automated testing to leverage the strengths of both approaches. Manual testing is helpful for exploratory testing and complex scenarios, while automated testing is efficient for repetitive tasks and large test suites.

Report defects effectively

Communicate defects clearly and concisely to developers. Provide detailed descriptions, steps to reproduce, and expected vs. actual results.

Track and manage defects

Use a defect tracking system to keep track of bugs, prioritise fixes, and monitor progress towards resolution.

Conduct test reviews

Regularly review test cases and procedures to ensure they remain relevant and effective. Update tests as the software evolves to maintain coverage.


Software testing and debugging, though distinct processes, are both indispensable elements of the SDLC. Testing, a proactive approach, focuses on preventing defects from entering the software, while debugging, a reactive approach, addresses defects identified during testing. By employing a combination of these two processes, software teams can deliver high-quality products that meet user expectations and ensure a seamless user experience. By adhering to the best practices outlined in this article, software testing can be a powerful tool for achieving software excellence.

If you are still searching for a reliable testing services company in Viet Nam, don’t hesitate to contact AgileTech. Our comprehensive software testing services can help you identify and eliminate defects, ensuring that your software meets the highest standards of quality and performance. Contact us today to learn more about how our experienced testers can help you deliver software that exceeds expectations. Don\’t let defects compromise your software\’s reputation!