What is Software Testing? Learn Software Testing Basics Step by Step

Software testing is the process of carefully checking a software application to find and fix any errors or bugs before it is released. Think of it as a thorough quality check to ensure the software works as expected, meets user needs, and delivers a smooth, reliable experience. This helps prevent issues that could cause problems or frustration later, ensuring the final product is both dependable and effective.

What is Software Testing?

 Software testing is the process of checking whether a software application works as expected. It helps identify bugs, missing requirements, and quality issues before the product is released. The goal of testing in software engineering is to ensure that the application is stable, secure, and performs well under all expected conditions. It is a crucial phase in the development cycle that verifies both the functionality and reliability of the product before it reaches users.

Objectives of Software Testing

​​If software testing is like preparing a meal for a special occasion, what are our primary goals or objectives for this preparation? Why do we put in all this effort? Here are the direct objectives of software testing:

• Ensure Reliability: Just as you’d want your dish to be consistently delicious every time you prepare it, we test to ensure the software is dependable and won’t disappoint you when needed.
• Verify Functionality: It’s like ensuring all the ingredients in a recipe come together ideally. In software, we verify that every feature functions as intended.
• Identify Defects: Before serving a dish, you’d want to ensure it tastes right and has no unwanted elements. Similarly, testing helps spot and fix any issues or bugs in the software. It’s essential to be aware of common pitfalls, as highlighted in our article on software testing errors to look out for.
• Assess User Experience: Just as the presentation and taste of a dish enhances your dining experience, a user-friendly software interface ensures a delightful digital journey.
• Maintain Quality Standards: Just as dishes must meet specific culinary standards, the software has quality benchmarks it needs to meet.

Evolution of Software QA Testing

1948: The Beginning
Tom Kilburn executed the first piece of software code to perform mathematical calculations. At that time, debugging was the only recognized testing activity.

1980s: Standardization Begins
The IEEE introduced the 829 Standard for Software Test Documentation, setting formal guidelines for test plans, test cases, and test results. This marked a shift from ad-hoc testing to structured software testing methods.

1990s: Emergence of Testing Tools
With software complexity growing, teams began using dedicated software testing tools and frameworks. Manual testing still dominated, but the groundwork for software testing types and processes became more defined.

2000s: Rise of Test Automation
Open-source tools like Selenium, JUnit, and TestNG emerged, making software testing automation more accessible. Teams started integrating automation into CI/CD pipelines to speed up releases.

2010s: Shift Toward Agile and DevOps
Testing became more integrated into the development lifecycle. Agile and DevOps practices emphasized continuous testing, faster feedback loops, and cross-functional collaboration.

2020s: AI and GenAI in Testing
With growing application complexity, AI in software testing began to play a major role. Tools started using machine learning for test case generation, defect prediction, and maintenance.

Generative AI in software testing further enabled testers to auto-create scripts and documentation using natural language inputs.

What Are the Benefits of Software Testing?

The benefits of software testing are described in the table below, showing how it improves the product, along with practical examples:

Understanding the cost of defects highlights why software testing is essential in preventing expensive and critical failures.

Principles of Software Testing

To get the best test results, in the end, this testing process should be conducted properly. For that reason, a set of principles are being followed in the software industry.

1. Exhaustive testing is not possible

In Exhaustive testing, specific functionality is tested using all possible combinations of inputs (valid and invalid). If the software is tested at every test case, then it may cost more money and hard work and, it becomes time-consuming as well.

As it seems impractical to follow, only an optimal number of test cases are executed, and based on their result the software product is considered correct.

2. Defect clustering

It has been identified that, in a project, a small number of modules can contain most of the defects. This is based on the Pareto Principle in software testing: 80% of software defect comes from 20% of modules. 

3. Pesticide Paradox

Executing the same test cases many times will make it lose the ability to trace new bugs or defects in the software. Therefore, a time-to-time review of the test cases should be done to find more new bugs.

4. Testing shows the presence of defects

Software testing always points out the defects in the application. It never discusses or claims zero defects. Even after running multiple test cases, the application cannot be considered bug-free. Therefore, testing can only reduce the number of bugs but, cannot eliminate all of them.

5. Absence of error – the fallacy

If the software is tested as 99% free but, still does not meet the customer’s requirement, then the product is considered unusable. Therefore it cannot claim that a 99% bug-free application must also meet the customer requirements.

6. Early testing

To detect defects at the earliest, it is important to do testing from the first phase of SDLC. Testing that is performed during the requirement analysis phase (the first phase of the SDLC) may cause to increase its performance.

7. Testing is context-dependent

Based on the context of the developed software, the testing approach is chosen for testing. The same testing approach may not be suitable for all types of software.

Types of Software Testing

Software testing types can be broadly categorized into functional and non-functional testing. Both are essential to validate that the software behaves as expected and performs well under various conditions.

1. Functional Testing

Functional testing verifies that the software functions according to the defined business and technical requirements. It focuses on what the system does. 

• Unit Testing

Tests individual components or functions of the software in isolation.
Example: Testing if a calculator app correctly adds two numbers.

• Integration Testing

Checks how different modules or services interact with each other.
Example: Verifying if the payment module correctly interacts with the order system.

• System Testing

Evaluates the complete system to ensure it meets all specifications.
Example: Testing an entire e-commerce application from login to checkout.

• Acceptance Testing

Confirms that the software meets business requirements and is ready for release.
Example: Running user scenarios to validate that product features align with client expectations.

2. Non-Functional Testing

Non-functional testing focuses on how the system performs rather than what it does. It measures aspects like speed, security, and user experience.

• Performance Testing

Assess the system’s speed and stability under load.
Example: Testing if the app handles 1000 users without slowing down.

• Security Testing

Identifies vulnerabilities and ensures data protection.
Example: Validating login security and encryption for sensitive user data.

• Usability Testing

Evaluates how user-friendly and intuitive the application is.
Example: Testing if users can complete a registration form without confusion.

• Compatibility Testing

Ensures the application works across different devices, browsers, and operating systems.
Example: Verifying that a mobile app works on both Android and iOS platforms.

• Integration testing 

Individual modules of an application are combined and tested to verify if they are working as they intend to when integrated.

This type of testing assumes that units/modules have been tested individually. Integration testing can be done by using two approaches.

Can they be automated? Yes, integration testing can be automated.

Should they be automated? Yes, automating integration testing can save time and improve accuracy.

Software Testing Best Practices

To ensure a structured and effective testing process, here are some of the best practices in software testing:

• Clearly define the expected output for each test case.
• Developers should avoid testing their own code to eliminate bias.
• Organizations should not test their own software to ensure objectivity.
• Analyze each test result carefully to spot patterns or recurring issues.
• Write test cases that include both valid and invalid inputs.
• Perform negative testing to uncover hidden vulnerabilities.
• Avoid low-value test cases that are costly to execute and offer minimal insights.

Software Testing Models

Various software testing models guide the testing process and define its phases. Some common models include:

• V-model: This model follows a V-shaped process, with each testing phase linked to its corresponding development phase.
• Waterfall model: Similar to the V-model, testing occurs sequentially after development phases are completed.
• Agile model: Testing is integrated throughout the development process in short iterations.
• Spiral model: Combines elements of iterative and sequential models.
• Test Pyramid model: Emphasizes a balanced testing approach with more unit and integration tests than UI tests.

The choice of model depends on the specific project requirements and team preferences.

What Can Be Automated within Software Testing?

Many aspects of software testing can be automated, including:

• Repetitive tasks: Automating repetitive tasks like regression testing can free up tester time for more complex tasks.
• Data-driven testing: Automated testing can be driven by data to test different scenarios and configurations.
• UI testing: Tools can be used to automate interactions with the user interface.
• API testing: Tools can be used to automate tests for application programming interfaces (APIs).
• Performance testing: Tools can be used to automate performance testing tasks such as load testing and stress testing.

While automation plays a vital role in modern software testing, it’s essential to remember that it cannot replace manual testing entirely. .

Why Choose Testsigma for Automated Software Testing?

Testsigma is an Agentic AI-powered codeless test automation platform designed to simplify and scale software testing for modern teams. From mobile, desktop, and web to enterprise apps like Salesforce and SAP, Testsigma brings together everything you need for fast, reliable, and collaborative testing in one place.

Here’s why Testsigma is a strong choice for your software testing needs:

1. Codeless Test Automation

Author tests in plain English using NLP or use the Generator Agent to create tests from prompts, Jira tickets, Figma designs, screenshots, images, videos, and PDFs. Empower both technical and non-technical teams to create, run, and manage tests without writing code.

2. Unified Platform for All App Types

Automate tests across web, mobile, desktop, and enterprise applications, including Salesforce and SAP, on a single platform with consistent workflows.

3. Real Device Testing 

Run cross-browser and cross-device tests on a cloud of over 3000+ real devices and browsers to ensure compatibility across environments.

4. Parallel Testing for Faster Releases

Accelerate execution with parallel testing capabilities that allow you to run multiple tests simultaneously across devices and browsers.

5. Built-in Integrations

Connect seamlessly with CI/CD tools, project management platforms, and bug trackers like Jenkins, GitHub, Jira, and more.

6. Advanced Reporting & Insights

Get clear, real-time test reports with detailed logs and screenshots to debug faster and keep stakeholders informed.

7. Self-Healing Test Maintenance

Powered by AI, Testsigma automatically detects UI changes and heals broken tests, reducing the effort spent on test maintenance.

8. Scalable for Growing Teams

Whether you’re a startup or an enterprise, Testsigma’s cloud-based architecture supports growing test suites and scaling teams without added complexity.

Conclusion

Software testing plays a vital role in building high-quality applications. It ensures that the product meets customer expectations, is free of critical bugs, and performs well under real-world conditions. Choosing the right software testing types and tools while following proven practices helps streamline the process and improve test outcomes.