In software engineering, often, individual units of source code are tested to determine whether they are fit for use or not. This way of software testing method is also called the unit testing. This testing ensures that the source code developed by a software engineer or developer meets the design specifications and works as intended.

On the other hand, the goal of unit testing is to separate each part of the program (that is, in a modular way). Then try to observe if all the individual parts are working normally. There are several benefits of unit testing in any software system:

• Find problems early: It finds bugs or missing parts of the specification early in the development cycle.
• Facilitates change: It helps in refactoring and up gradation without worrying about breaking functionality.
• Simplifies integration: It makes integration tests easier to write.
• Documentation: It provides a living documentation of the system.
• Design: It can act as the formal design of the project.