In this tutorial we are going to learn about the differences between Error, Bug, Defect, and Failure.

Error:
Error is an incorrect human action or mistakes done by the human-like developer may write the code incorrectly.

Defect:
The Error found by the tester is called a defect.

Bug:
The Defect accepted by the development team is called the Bug.
or
The deviation from the expected behavior and the actual behavior is called a Bug.

Failure:
The deviation identified by the end-user while working with the software is called failure.

Why software has Bugs?

1. Miscommunication or no communication between developers and testers.
2. Software Complexity.
3. Programming errors.
4. Changing requirements.
5. Lack of Skilled testers.