Hye...
If you are beginner here and want to know about trading so you are at right place.
some people want to know about this option so here limit means that you are buying this coin at specific rate .
if you order it on specific rate ,so you can order to sell it t the same time but in the limit section you have to put the rate at which you want to sell it.
and then automatically it will be selling at the time coin reach the rate you have put in this section.
For example you are buying at 2.5$ and then again by going to selling option you order it to sell at 2.7$.
This is All what it means!!