??? Your appliances should be provided with a ground conductor who's source would be from the ground conductor provided at the service entry.
The appliance itself should have the facility already if it does require an earth ground.
Max.
American,UK sockets have third pin that is generally longer then power pins so it gets grounded before power flows in.European has 2 clips on side that make connection when plug is half way in the socket.
Other posters have referred to appliances that are called portable appliances. Broadly speaking these are designed to be plugged in and unplugged and moved about.
Examples are your television, toaster, hair curlers, side lamps etc.
Other sorts of appliances may be fixed appliances. These will be permanently wired in and not pluggable/unpluggable.
Examples are cookers, water heaters, space heaters, air conditioners, shower units, fixed lighting.
In the EU/USA/CAN, major appliances (Washer/Dryer/Refrigerators/Freese/Stoves/MicrowaveOvens) come with three-wire power cords, where the third prong is supposed to be connected to Earth (Safety) Ground through the existing building wiring.
Are you asking how a house is supposed to be wired? That is covered by various wiring Codes which apply in your country, and since you didn't put in a country when you registered for the forum, we have no clue where you are...