is performed by a select group of end users before the software is released to the public.

10. is performed to determine how a system performs under different conditions.

9. is performed to verify the interaction between different software modules.

Regression testing is performed to ensure that changes or fixes in the software do not introduce new .

In beta testing, the software is tested by a group of potential users in a environment.

In , developers review the program code to find defects and suggest improvements.