What is "my signature"

[chixcoop]

I was exploring the website, and I was wondering what edit my signature was. So I clicked on it and it "did not permit me" what is "My signature" and why can I not edit it?

 

[TwoCrows]

Your signature is the section beneath your profile here as you post. See mine with the links to articles etc....

You should be able to add a signature to your profile after you have about 20 posts. So only a few more to go!