Meaning of word "celebrity"

Hello! How are you?.

Honestly, I get confused when I talk

about famous people and celebrities.

What is really a celebrity?

Some examples:

1.- Madonna is a famous person. Is he a celebrity
as well?

2.- What about all those people who sell
an exclusive in the press?. They are famous.
And celebrities as well? Maybe celebrities
in an ironical sense?

3.- A criminal can be famous, but can he
be a celebrity as well?. For instance,
the man who killed John Lennon.

4.- Someone becomes famous by cheating,
by telling a lot of lies in the media.
Is he a celebrity? Maybe a celebrity in an ironical sense too?

If my examples were wrong,
please give me some and make
the term “celebrity” clearer
for me.

Thanks indeed!

Hi Jesus

I’ve written a few comments in the quote (in blue).

Amy

Hi Amy, you nicely answered for the questions. Very helpful for people like me too. Really appreciate it.