Introduction
In software engineering, understanding different types of testing is extremely important for every QA tester. Each testing type has a specific purpose and is performed at different stages of the development cycle.
In this guide, we will explain all major testing types used in real companies with practical examples.
1. Functional Testing
Functional testing verifies whether the application works according to business requirements.
- Login functionality
- Form submission
- Button clicks
- Data validation
Example: Checking whether the user can successfully log in with valid credentials.
2. Non-Functional Testing
Non-functional testing checks performance, security, usability and other quality aspects.
- Performance Testing
- Load Testing
- Security Testing
- Usability Testing
Example: Checking if the website loads within 2 seconds under heavy traffic.
3. Smoke Testing
Smoke testing verifies basic functionality of a build before detailed testing begins.
Example: Checking login, homepage loading and main navigation after deployment.
4. Sanity Testing
Sanity testing checks specific functionality after minor code changes.
Example: After fixing login bug, tester verifies only login module.
5. Regression Testing
Regression testing ensures that new changes do not break existing functionality.
Example: After adding payment feature, tester verifies cart and checkout still work.
6. Integration Testing
Integration testing verifies interaction between modules.
Example: Checking whether login module correctly connects with database.
7. System Testing
System testing verifies the complete application as a whole.
Example: Testing full e-commerce flow from product search to payment.
8. Acceptance Testing
Acceptance testing is performed to confirm whether the system meets business requirements.
- User Acceptance Testing (UAT)
- Alpha Testing
- Beta Testing
Summary
Each testing type plays a critical role in delivering high-quality software. A good QA engineer understands when and how to apply each testing type.
Frequently Asked Questions
What are the main types of testing?
Functional, Non-functional, Regression, Smoke, Sanity, Integration, System and Acceptance testing.
What is difference between smoke and sanity testing?
Smoke testing checks basic build stability, while sanity testing verifies specific fixes.
Is regression testing important?
Yes. It ensures new changes do not break existing features.