What is the purpose of Signature?

Im a new member here. Im an old player but, i dont play all the time. This is my first time joining a forum so i dont really have that much of an idea what I can do here. So as the title say, what is "signature"? what`s its purpose here? Any tips that you can give about forums would be great

 

well, it's a signature...
it will displayed under each of your posts, like some official personal stamp mark.
usually people use it to brag about their status or achievements.

and yokoso to the forums

 

oh ok. so it doesn't really matter if I have one or not. Thanks