Each chip has a unique bar code number. All the chip numbers are registered with a database, who can then supply the owner and animals details. Name, address, contact numbers, breed, colour, veterinary information can all be included on the database. We charge £20 for a chip & registration. We chip most cats we neuter nowadays.
You should get an official microchip certificate once registration is complete (in the UK, the vets normally register chip) with details on how to change address/numbers, etc, for a small charge.
All vets, shelters, rescue organisations, police stations, etc should have a microchip scanner. The chip is inserted between the cat/dog's shoulderblades.