Is Oracle different from Oracle's MySQL?

In the IT development process of the six-month state-funded course

Today, we've started a new journey with a book called Oracle SQL and PL/SQL, which are easy to learn with a variety of examples.

There is a DBMS, a professional program that manages data rolls in books, among them

Oracle

MSSQL (MicroOffice)

DB2 (IBM)

MySQL (Oracle)

Tibero (domestic)

It's like this.

Is it different from MySQL provided by Oracle 1 and Oracle 4?

Even if I search, I think they are both from the same Oracle company, but I'm confused