Role of Documentation

Hello Olive, as you might be knowing there are various types of testing (Unit Testing, System Testing, etc...). So in the testing we are actually checking the functionality of our application. We check how our application works, does it provides us our desired O/P, does the application contains any bugs and many other things are being checked while testing the app.

And I am not the only person who is going to test the application. There will be many more in our company who will test the same application but with a different scenario and testing inputs. 

So when we test an application, we have to document, in simple words (Note down our I/P and O/p) somewhere in a word document or anywhere else so that in future if some other person comes and tests the same application, he already knows what all things have been tested and what O/P we got. 

So the Documentation becomes a help to the other person while he/she is testing. Documentation is very important since it also helps us to understand what features we can add more to improve our application...

Google it up for more information!!!

Hope this answer helps u to understand the need of Documentation in short.