please, what cheating means?
how to?

How do I report someone I think is cheating?
If you are suspicious about somebody cheating, please use the Report Abuse link and include all relevant information. We investigate all reports.
http://www.chess.com/forum/view/community/cheating-at-chess-on-chesscom---questions-and-answers
(This topic - written by Erik - is pinned at the top of the Unanswered Posts).
How do I report someone whom I believe is cheating?