what meaning STAR in mylot...

As ownado said, those starts are just rating you answers / replies / discussions here at myLot.com. I must add that the rating is mostly made by other users that can rate you with + / - (if you noticed these buttons are near every user's post). Many +'s would increase your rating while many -'s would decrease it of course. There's aso a 3rd sign, "!", that means report that post for breaking the myLot's posting rules.

The stars are a kind of rating of your participation here on myLot. The more you post good and meaningful messages the more they will go up until the 10. Keep on posting on good discussions and they'll increase, good luck!