What key fob programming covers
Key fob programming is the broad service for getting a fob to work with your vehicle. Depending on the key, that can mean pairing remote buttons, registering an integrated remote-head key so it both starts the car and works the locks, or registering a proximity smart fob. Some jobs involve only the buttons; others involve the immobilizer as well. Which applies depends on the fob design and the vehicle.
Remote pairing and starting authorization are different steps
On many vehicles the lock and unlock buttons use one system and permission to start the engine uses another. A fob can open the doors and still not start the car, or start the car while its buttons do nothing. If you only need buttons paired on a remote that does not start the car, the remote programming page is narrower. If the fob must start a push-button car, the push-to-start keys page covers that.
Checking the fob before programming it
Fobs that look identical can carry different part numbers, FCC IDs and frequencies, and some used fobs cannot be set up again. I check the fob against your vehicle before programming, and I check for a dead coin cell or damaged buttons first so you don't pay for programming a fob that only needed a battery. Remote start and other buttons work only if the vehicle is equipped for them.