Why do Mysql, Mysqld, Mariadb work at the same time?

Question

MySQL

I started having problems with MySQL server on Centos 7. MariaDB works there.
When I look at the list of services, I see the whole trinity there: Mysql, Mysqld, Mariadb

Here is a status query
[[email protected]=~]# service mysql status
ERROR! MariaDB is not running
[[email protected]=~]# service mariadb status
Redirecting to /bin/systemctl status mariadb.service
● mariadb.service - MariaDB 10.2.17 database server
[[email protected]=~]# service mysqld status
Redirecting to /bin/ systemctl status mysqld.service
● mariadb.service - MariaDB 10.2.17 database server
Is this normal, or do I have some duplicate services?