1. Unit Testing
Definition:
Unit testing involves testing individual components or units of code in isolation to verify that they work as expected. It’s typically performed by developers.
Purpose:
- To ensure that each unit of code (usually a function or method) performs its intended task correctly.
Tools:
- JUnit (Java), NUnit (.NET), PyTest (Python), Google Test (C++)
Example:
Testing a function calculateTotalPrice() in an e-commerce app that calculates the total price of products in a cart.
2. Integration Testing
Definition:
Integration testing focuses on testing the interaction between multiple components or modules that have already been unit tested.
Purpose:
- To verify if different modules or services of the application work correctly when integrated.
- To detect issues such as data mismatches, incorrect API responses, and communication failures between modules.
Tools:
- Postman (API), JUnit, SoapUI, RestAssured
Example:
Testing if the user authentication module communicates properly with the database module to verify credentials.
3. System Testing
Definition:
System testing involves testing the entire application as a whole. It checks the integration of all components to ensure the system works as expected.
Purpose:
- To validate the complete and integrated software application against business and functional requirements.
- To detect bugs that may arise from the interaction of components.
Tools:
- Selenium, TestComplete, QTP
Example:
Testing an e-commerce website end-to-end, ensuring features like user registration, shopping cart, and payment processing work together.
4. User Acceptance Testing (UAT)
Definition:
User Acceptance Testing is the final testing phase where end-users validate whether the software meets their needs and expectations.
Purpose:
- To ensure that the software fulfills business requirements and is ready for deployment.
- UAT typically occurs after system testing and before the product is released to the market.
Tools:
- Can be manual or automated, often using business-oriented tools like Jira, TestRail.
Example:
A banking application is tested by actual bank staff to ensure it correctly processes transactions and adheres to business policies.
5. Regression Testing
Definition:
Regression testing involves retesting the application after changes such as updates, patches, or new feature additions to ensure that previously working functionality has not been broken.
Purpose:
- To ensure that new changes don’t negatively affect the existing features of the system.
Tools:
- Selenium, QTP, JUnit, TestComplete
Example:
After adding a new payment gateway integration in an e-commerce app, regression testing ensures that the existing checkout process still functions correctly.
6. Smoke Testing
Definition:
Smoke testing is a quick, initial round of testing to ensure that the basic functionalities of the software work as expected. It’s often called a “sanity check.”
Purpose:
- To quickly identify major failures in critical functionalities before more detailed testing begins.
Tools:
- Typically manual, but can be automated using tools like Selenium.
Example:
After deploying a new build, smoke testing checks if the login functionality and home page loading work before proceeding with further tests.
7. Stress Testing
Definition:
Stress testing evaluates how the system performs under extreme conditions, such as high traffic or heavy workloads, beyond normal operational limits.
Purpose:
- To determine the breaking point of the application and check how it recovers from failure.
Tools:
- LoadRunner, JMeter, Apache Bench
Example:
Simulating 5000 concurrent users trying to place orders at the same time in an e-commerce website.
8. Performance Testing
Definition:
Performance testing checks how well the system performs in terms of speed, responsiveness, and stability under various conditions.
Purpose:
- To measure the system’s response time, throughput, and resource usage under normal and peak load conditions.
Tools:
- LoadRunner, JMeter, New Relic
Example:
Measuring the response time of a hotel booking website when 1000 users search for hotels simultaneously.
9. Load Testing
Definition:
Load testing evaluates the system’s ability to perform under a specific load (e.g., number of users or transactions).
Purpose:
- To test if the system can handle anticipated peak loads without crashing.
Tools:
- JMeter, LoadRunner, Blazemeter
Example:
Testing if an online exam platform can handle 1000 students attempting to log in at once.
10. Security Testing
Definition:
Security testing ensures the application is free from vulnerabilities, such as data breaches, unauthorized access, and cyber-attacks.
Purpose:
- To identify potential security loopholes in the system and ensure sensitive data is protected.
Tools:
- OWASP ZAP, Burp Suite, Kali Linux
Example:
Checking if a banking website properly encrypts user data and prevents unauthorized login attempts.
11. Compatibility Testing
Definition:
Compatibility testing verifies that the application works as expected across different environments (e.g., operating systems, browsers, devices).
Purpose:
- To ensure that the application provides a consistent user experience on different platforms.
Tools:
- BrowserStack, CrossBrowserTesting, Sauce Labs
Example:
Testing a responsive website to ensure it works correctly on Chrome, Firefox, Safari, and mobile browsers.
12. Usability Testing
Definition:
Usability testing focuses on evaluating the user experience (UX), ensuring the application is intuitive, easy to navigate, and user-friendly.
Purpose:
- To ensure that the system is easy to use and meets user expectations for interaction.
Tools:
- UserZoom, Lookback, Crazy Egg
Example:
Evaluating how easy it is for a first-time user to navigate a banking app and complete a transaction.
13. Acceptance Testing
Definition:
Acceptance testing verifies if the software meets user and business requirements and is ready for deployment.
Purpose:
- To validate whether the software fulfills its intended purpose from a business and user perspective.
Tools:
- Jira, TestRail
Example:
A restaurant management system is tested to ensure it correctly handles order placement, inventory management, and bill generation.
14. A/B Testing
Definition:
A/B testing is a method of comparing two versions of a webpage, app, or feature to see which one performs better.
Purpose:
- To make data-driven decisions about design, functionality, and UX.
Tools:
- Optimizely, Google Optimize
Example:
Testing two different call-to-action buttons on an e-commerce site to see which one leads to higher sales conversions.
