Final answer:
Schwann cells are derived from neural crest cells and their job is to produce the myelin sheath in the peripheral nervous system. They are located in the peripheral nervous system, surrounding and supporting individual axons.
Step-by-step explanation:
Schwann cells are a type of glial cell that produce the myelin sheath in the peripheral nervous system. They are derived from neural crest cells during embryonic development. Schwann cells play a crucial role in insulating axons and promoting faster transmission of nerve impulses. They are located in the peripheral nervous system, surrounding and supporting individual axons.