Go here where I wrote a whole friggin essay on this topic.
In the future, you need to use the find feature at the top of the page (it's a little tab) and search for very general topics. These type of questions have been asked a million times. Save your posts for detailed, specific questions after you've got the general jist of everything.
And don't give dumb thread titles. More people will click on your thread if they get an idea of what's inside. I don't answer threads about infantry cause I'm not a grunt, but I'll go in female specific threads and topics that I know I'm informed about.
