Can someone explain twitter to me?

[knz]

So I made twitter just to follow some of my favorite musicians, but then forgot about it and never went on again. I recently went on and had 26 followers and I don't get what that means? I don't know any of them, so how did they follow me? How do I get more followers? And what are hashtags and how do they work? Thanks! (Sorry I'm a social media idiot.)

[hardik]

In settings of your twitter account make your account private(every new request notify you that you want him to following you or not?)
2.It matters on your interest.
3.Hash tag is mainly used for searching specific topic in twitter search box.
e.g. suppose you have written tweet like: #tweeter user.
means that when you search #tweeter in tweeter search box then it will give all tweets which include #tweeter.