Give one basic functional difference between phellogen and phelloderm?

The basic functional difference between phellogen and phelloderm is:

Phellogen is a meristematic tissue and Phelloderm is a permanent tissue.

Phellogen is called as Cork Cambium, Phelloderm is called as Secondary Cortex.

Phellogen develops from the cortical cells, sometimes from pericycle cells. These cells actively divide and forms phellem on outer side.

Phelloderm inner side on so phelloderm takes its origin from phellogen.

Phellogen produces phellem and phelloderm.

Phelloderm stores food materials.