Here's a breakdown:

* Oocytes: The egg cells themselves are called oocytes.

* Follicle: An oocyte is surrounded by a layer of supporting cells called granulosa cells. This entire structure is called a follicle.

* Maturation: As an egg matures, the follicle grows and develops. The granulosa cells produce hormones that help the egg to mature.

Let me know if you'd like to learn more about the process of egg maturation!