If something is damaged you can usually see the damage but not always, the object can usually be repaired. If something is ruined, it may be noticeable but not always and it is beyond repair. If something is destroyed it is always noticeable and the structure of the object has changed and it is beyond repair and possibly recognition.

thx,I'll take it.

Please use "I'd like to know the difference..." when asking questions. Sorry to tell you this, but your slang phrasing sounded childish.