On what device and in what form are tables created using a relational DBMS stored?

With the help of the DBMS, you will create tables and save them to disk as files. Each file has its own name. If you create a table yourself and save it to a file, you yourself come up with a name for the file. If you want to work with a ready-made database, then you must find out in the file with what name, on which disk and in which directory it is stored.