What type of pronoun is all?

The pronoun 'all' is a indefinite pronoun, a Word standing in for the whole quantity of something. The indefinite pronoun 'all' is used as a singular or a plural. Examples:

All of it is yours.

All have arrived.

The Word 'all' is an adjective when placed just before a noun to describe the noun:

All parents will be notified of the changes.