What is Software Testing?

Software testing is the process of evaluating and verifying that a software application or system meets its specifications and works as expected. It involves executing software or its components to identify bugs, errors, and any inconsistencies that may exist in the code.

Testing is typically divided into different levels, including:

1. Unit Testing: This is the first level of testing and focuses on individual components of the software. Unit tests ensure that each piece of code works in isolation as expected.

2. Integration Testing: Once the individual units are tested, integration testing checks how different modules or components interact with each other. The goal is to identify issues in the way various parts of the software interact.

3. System Testing: This is a more comprehensive level of testing where the entire application is tested as a whole. System tests evaluate whether the software meets all functional and non-functional requirements, including security, usability, and performance.

4. Acceptance Testing: This is typically performed by the client or end-users to determine if the software satisfies their business needs and requirements. If the software passes acceptance testing, it's considered ready for deployment.

5. Regression Testing: After updates or bug fixes are made, regression testing ensures that these changes do not introduce new problems into the system.