What is the difference between count(0), count(1).. and count(*) in mySQL/SQL?

What is the difference between count(0), count(1).. and count(*) in
mySQL/SQL?

I was recently asked this question in an interview. I tried this in mySQL,
and got the same results(final results). All gave the number of rows in
that particular table. Can anyone explain the major difference between
them. P.S: Forgive me for any english mistakes.