Why is mariadb always installed when installing MariaDB and MySQL?

Question

MySQL

why do
apt-get install mariadb-server
and
apt-get install mysql-server
show mariadb in the result?
moreover, if you do the first option first, then in the second option the manager will not say that maridb is already installed

Answer 1

Because MySQL is now called MariaDB, and on many systems mysql will be a link to mariadb.
The old name and source codes are sold by Oracle and are accordingly developed and maintained separately.
Until now, often when they say MySQL they mean MariaDB. And although the development of MariaDB and Oracle MySQL is very parallel, and most things appear in both branches, the differences will add up.
It is possible that you need MariaDB and not MySQL.