Character level

From BRWiki

A Character level is the total level of the character, which is the sum of all class levels held by that character.

A Class level is the level of a character in a particular class. For a character with levels in only one class, class level and character level are the same.

As a character's class level increases, they receive access to new abilities and improve existing ones.

This is partially quoting from the D20 SRD.