Follower List?

What does it mean if I got a message that someone has been added to my follower list?  I have never used a follower list and don't understand what it means.  The message also states that I can accept or block.  Can someone please explain.  Thanks very much.

I expect it means they get an update message when you post something. It's for people to keep track of people they think they have something in common with. 

moorspede said:

 
I expect it means they get an update message when you post something. It's for people to keep track of people they think they have something in common with. 

Click to expand...

Okay, thanks for the explanation.   I wasn't sure what it meant.