1.4 Widely employed Types of Testing

From the V-model, we see that are various levels or phases of testing, namely, Unit testing, Integration testing, System testing, User Acceptance testing etc.
Let us see a brief definition on the widely employed types of testing.

Unit Testing: The testing done to a unit or to a smallest piece of software. Done to verify if it satisfies its functional specification or its intended design structure.

Integration Testing: Testing which takes place as sub elements are combined (i.e., integrated) to form higher-level elements

Regression Testing: Selective re-testing of a system to verify the modification (bug fixes) have not caused unintended effects and that system still complies with its specified requirements
System Testing: Testing the software for the required specifications on the intended hardware

Acceptance Testing: Formal testing conducted to determine whether or not a system satisfies its acceptance criteria, which enables a customer to determine whether to accept the system or not.

Performance Testing: To evaluate the time taken or response time of the system to perform it’s required functions in comparison

Stress Testing: To evaluate a system beyond the limits of the specified requirements or system resources (such as disk space, memory, processor utilization) to ensure the system do not break unexpectedly

Load Testing: Load Testing, a subset of stress testing, verifies that a web site can handle a particular number of concurrent users while maintaining acceptable response times


Alpha Testing: Testing of a software product or system conducted at the developer’s site by the customer

Beta Testing: Testing conducted at one or more customer sites by the end user of a delivered software product system.