What usually happens at a police check? do they just look up your name in their system?

it depends on the kind of police check. like if its a road block type of check, they make sure everything is right. if you get pulled over you get your name ran in the system to check if you have warrents or warning and depends on what you get pulled over for, you could get a ticket or detained.

that without the operating systems you would have to control and synchronize computer hardware.

b and c ( ip address and port number)