Can anyone tell me what the star stand for??

well, the star denoted the rating. one will get his/her star only after making 100 posts. this rating is based on how far you had been active in making discussions and responding. also it is based the quality of your response and your best responses. the higher performance and higher the ranks. you can see the exact rating percentage by keeping your mouse over the star(which you would get only after 100 posts based on your previous performance).this gives the exact rating and it may not be viewed in few explorers. you can very well view it in internet explorer.. hope i have given you the best response possible !!! good luck!!!