What goes in /var?

Question

I read The Linux Command Line by William Shotts, and there are some descriptions of Linux files (system directories):

The /var directory contents don't change. This tree is where data that is likely to change is stored. Various databases, spool files, user mail, etc. are located here.

I am wondering: If the /var directory contents are not supposed to change, why is there a www directory in /var/www after installing apache-php?

The /var/www directory is where we must edit, create or delete files. This is a localhost public directory.

Why did he say, that the /var directory contents don't change?

Answer 1

I'd say that the contents in /var don't change so often. In my experience it's mostly used to store database files, cache files and of course, the /var/www directory. These objects do change but for example, a website doesn't change every second.