TWITTER?..what does it mean when people request to follow me?

[Betty]

Being a senior i cannot wrap my brain around the concept of twitter & Facebook, why do so many people ask to friend me? or request to follow me?... am i suppose to be actively doing something? I am following Ellen DeGeneres, but see no difference in what's going on than before i started following her, so why are these two sites so popular, &f i let someone befriend, or follow me, (how does the selection process work?)does that indicate to them that we are destined text pals? (Thank you & Happy holidays)