By default, MySQL stores all databases into one binary file.
This is a quick tip for the database engine MySQL/InnoDB.
MySQL creates and updates one binary file, containing your database data.
The problem is, that the filesize increases on every data insert, update and so on. If you delete a record / table / database, the file is still the same size. This can be very inappropriate if your server disk space is limited.
With the command
SET GLOBAL innodb_file_per_table=1;
you can change this behavior. MySQL will create a file for every next database. This file can be removed it, if the database gets deleted as well.
Please comment below, if you have any questions.