Magic Bands are RFID wrist bands that are used for Fastpasse+ and purchases at Walt Disney World Parks and Resorts.
Magic bands hold all of your Fastpass+ reservations and is used by touching the wrist band to the post with the circular mickey RFID reader in Fastpass + lines.
Purchases can be made at all shops, restaurants, and most snack carts using your Magic Bands. You must be staying at a Walt Disney World Resort and have set up a pin in order to use the Magic Band for purchases.
The magic band does not hold your personal information. It does allow access to ride videos, ride pictures, and Photopass on the My Disney Experience App. It also acts as your room key and park entry.
You do not need to have a Magic Band if you are not staying at a Disney Resort. Your park ticket will also have an RFID chip that can be used for park entry and Fastpass +. You will not have any charging privileges.