What does those star means??

I'm not sure that I understand your question completely will but will attempt to answer what I know. The numbers in the stars are called the star rating, the numbers range from 1 through 10 the higher the star the higher your mylot reputation. Other members rate you on your responses and to the starting of your discussions, the rate you based on the quality. If you answer the discussion with a 1 liner a lot of mylotters will either rate you negatively or will simply not rate you at all. So the best thing to do is respond with quality answers make sure that you stay on topic. Welcome to mylot, I hope this helps. :)

You get the star next to your name after you have made 100 posts. The numbers in the middle are, as pointed out, the rating on the quality of your posts. So the higher the number, the better your rating, as judged by your peers. The +, - & ! to the right next to each response is how you rate people. The more + people rate your responses, the higher that number inside the star is.