What is Software Testing?

Software Testing is the process of evaluating and verifying that a software application functions as expected. It ensures that the software meets requirements, is free from defects, and performs well under different conditions.

Software testing can be classified into Manual Testing and Automated Testing, and it includes different testing methodologies like Functional Testing, Non-Functional Testing, White Box Testing, and Black Box Testing.

Types of Software Testing

1️⃣ Functional Testing (Validates Software Features & Business Logic)

Functional testing checks whether the software works as expected by verifying its functions against the specified requirements.

1. Unit Testing

Tests individual components (functions, methods, modules).
Performed by developers using frameworks like JUnit, PyTest, NUnit.
Example: Testing a “calculateTotalPrice()” function in an e-commerce app.

2. Integration Testing

Tests interactions between integrated modules to ensure seamless communication.
Example: Checking if the user login module correctly communicates with the database.

3. System Testing

Evaluates the entire system to verify compliance with business requirements.
Example: Testing an online banking system from login to fund transfer.

4. User Acceptance Testing (UAT)

Conducted by end-users to verify if the software meets their needs.
Example: A retail company tests an ERP system before final rollout.

5. Regression Testing

Ensures new changes do not break existing functionality.
Example: Running old test cases after adding a new search feature in a website.

6. Smoke Testing

Quick tests on major functionalities before detailed testing.
Example: Checking if a newly deployed web app loads properly.

7. Sanity Testing

Focused checks on specific bug fixes or new features.
Example: Verifying if a login issue reported by users has been fixed.

8. Alpha Testing

Conducted by internal testers before external release.
Example: Google’s internal employees test a new Gmail feature before the public release.

9. Beta Testing

Conducted by real users in a controlled environment.
Example: WhatsApp launches beta versions for early user feedback.

10. Black Box Testing

Tests the system without knowing internal code structure.
Example: Inputting valid and invalid login credentials and checking responses.

11. White Box Testing

Tests the system with knowledge of internal code (e.g., paths, loops, conditions).
Example: Checking if a “for loop” correctly iterates through user records.

12. Grey Box Testing

Partially aware of the internal code and tests data flows between modules.
Example: Checking if a checkout page correctly applies discounts and tax calculations.

13. Boundary Value Testing

Tests extreme and edge values to check system stability.
Example: Checking password validation with 0, 1, and max-length characters.

14. Equivalence Partitioning

Divides inputs into valid and invalid partitions for efficient testing.
Example: Testing an age input field with <18, 18-60, and >60 categories.

15. Decision Table Testing

Uses tables to verify different input combinations and outputs.
Example: Testing a loan approval system where multiple conditions apply.

16. Exploratory Testing

Testers explore the software without predefined test cases.
Example: A tester randomly navigates a new mobile app to find unexpected issues.

17. Ad-hoc Testing

Unstructured testing done without documentation or formal planning.
Example: Clicking random buttons on an application to check for crashes.

2️⃣ Non-Functional Testing (Checks Performance, Security & Usability)

Non-functional testing verifies how well the system performs under different conditions.

18. Performance Testing

Measures system speed and responsiveness.
Example: Checking if an online store can process 100 orders per second.

19. Load Testing

Tests the system under expected traffic loads.
Example: Simulating 10,000 concurrent users on a social media app.

20. Stress Testing

Pushes the system beyond normal limits to find failure points.
Example: Checking how a banking app behaves under extreme transactions.

21. Scalability Testing

Evaluates how well the system scales as workload increases.
Example: Can a cloud-based video platform handle 1 million users?

22. Volume Testing

Tests performance with large datasets.
Example: Checking if a database can handle 1TB of customer data.

23. Endurance (Soak) Testing

Runs the system continuously to detect performance degradation over time.
Example: Testing an e-commerce website for 48 hours under heavy traffic.

24. Security Testing

Identifies vulnerabilities and threats.
Example: Checking if a banking app encrypts user passwords correctly.

25. Penetration Testing

Simulates cyber-attacks to test security defenses.
Example: Ethical hackers try to break into a company’s web application.

26. Vulnerability Testing

Scans for known security weaknesses.
Example: Checking for outdated software versions in a system.

27. Usability Testing

Ensures software is user-friendly and easy to navigate.
Example: Testing if a travel booking website is easy to use.

28. Accessibility Testing

Ensures compliance with standards for disabled users (WCAG, ADA).
Example: Checking if a screen reader works on a government portal.

29. Compatibility Testing

Ensures software runs on different browsers, OS, and devices.
Example: Checking if a web app works on Chrome, Firefox, and Safari.

30. Recovery Testing

Tests how quickly a system recovers after failure.
Example: Testing if an airline booking system restores data after a crash.

3️⃣ Specialized Testing (Industry-Specific & Advanced Testing)

31. API Testing

Ensures APIs return correct responses.
Example: Checking if a weather API correctly returns temperature data.

32. Mobile Testing

Tests apps on different screen sizes, networks, and OS versions.
Example: Checking an Android app on Samsung, Pixel, and OnePlus.

33. Cloud Testing

Ensures a system works properly in cloud environments (AWS, Azure).

34. IoT Testing

Tests Internet of Things (IoT) devices and connectivity.

35. Blockchain Testing

Ensures secure and accurate blockchain transactions.

36. AI/ML Testing

Validates AI model predictions and accuracy.

37. ERP Testing

Tests Enterprise Resource Planning (ERP) software like SAP, Oracle.

38. Data Warehouse Testing

Ensures large-scale data storage and retrieval works efficiently.

39. ETL Testing

Validates Extract, Transform, Load (ETL) data migration processes.

40. Chatbot Testing

Ensures chatbots correctly understand and respond to queries.

Conclusion

Software testing is critical for ensuring reliability, security, and user satisfaction. Functional testing ensures correct operation, non-functional testing checks performance & security, and specialized testing applies to specific technologies.1️⃣ Functional Testing (Validates Software Features & Business Logic)