1. its for registering a car to an owner in a system ( since for example, if you had a loan, the car isn't in your name till its paid, yet the bank is not the one held accountable for whatever bad descisions you make )
2. it setups a system they can reference your name via the plate issued, and then back check for example if you really have insurance
3. it also is used for tracking purposes of how many cars are in a city, how many cars you own (property taxes)
4. its another way for the government to get some money from you, just for buying a car
