Code review is systematic examination of computer source 
code intended to find and fix mistakes overlooked in the 
initial development phase, improving overall quality of 
software and can also be used as a tool to better develop 
skills at the same time.

Code review is review of the source code to intend to check
whether the source code met the following things or not?

1) To meet the organizational code standards.

2) To avoid the ambiguity of the code.

3) To delete unnecessary code.

4) proper re-use of the existing code. 

5) to improve the performance of the application.

6) To check the proper comments are added or not.

7) To check the code structure.