In one to two sentences, define revision

Study these definitions.

http://definitions.dictionary.net/revision

the changing of the content and organizing it in order to communicate the writers topic.

does this sound ok?

No.

You have one group of words that is not a sentence.

Revision is the changing and organizing of the contents in order to communicate the writers topic.

O.k. Be sure to make it WRITER'S with an apostrophe.

thank you very much

You're very welcome.