What are the different types of testing techniques used in the SDLC?

In the Software Development Life Cycle (SDLC), there are several types of testing techniques used to ensure the quality and reliability of the software being developed. These testing techniques can be broadly categorized into four main types:

1. Unit Testing: This type of testing focuses on testing individual components or units of the software. It involves testing each unit in isolation to ensure that it functions correctly and meets the specified requirements. Unit testing is typically performed by developers using frameworks like JUnit or NUnit.

2. Integration Testing: Integration testing is conducted to verify the proper functioning of different modules or components when integrated together. It aims to identify any issues or defects that may arise due to the interaction between these components. Integration testing can be performed using techniques like top-down, bottom-up, or sandwich testing.

3. System Testing: System testing is carried out to evaluate the entire system as a whole. It involves testing the software against the functional and non-functional requirements to ensure that it meets the desired specifications. System testing includes various techniques such as functional testing, performance testing, security testing, usability testing, and compatibility testing.

4. Acceptance Testing: Acceptance testing is the final phase of testing in the SDLC. It is performed to determine whether the software meets the user's expectations and requirements. This type of testing is usually conducted by end-users or stakeholders to validate the software's readiness for deployment. Acceptance testing can be done through techniques like alpha testing, beta testing, or user acceptance testing (UAT).

Apart from these main types, there are also other testing techniques used in the SDLC, such as regression testing, load testing, stress testing, and usability testing. The selection of testing techniques depends on the project requirements, complexity, and the level of risk associated with the software being developed.