Where are $_SESSION variables stored?

In PHP, $_SESSION variables are typically stored on the server in a file or a database. For example, when using the default session handler, PHP stores session data in files on the server in a specific directory. The location of this directory is determined by the session.save_path setting in the php.ini file. By default, it is "/tmp" on unix systems.

Alternatively, it can be stored in a database by configuring session handlers, like SQLite, MySQL, or Memcached.

To store in a database, you would need to create a table to hold the session data and then use the session_set_save_handler function to specify which database table to use for storing session data.