Ceiling roses are common in UK properties. Typically, one was fitted in each room, located in the centre of the ceiling.
As before, the cable marked 'IN' is the supply from the consumer unit or another ceiling rose. This contains live, neutral and earth wires. These are permanently connected to the supply.
The cable marked 'OUT' connects in exactly the same way, and carries the power to the next ceiling rose, probably in the next room.
The 'SWITCH' cable connects to a one way switch and the 'LAMP' cable connects to the light bulb or lamp.
As with the previous example, all of the neutral wires connect to the neutral terminal. Permanent live wires connect to the Loop terminal, and all earth wires connect to the earth terminal.
The switch connects between the Loop and Live terminals, so the live terminal is only live when the switch is on.
Some installations may have additional OUT cables. These are all connected in the same way, to Neutral, Earth and Loop.
Only the switched live and the lamp connect to the Live terminal.
people don't connect the 'OUT' cable properly?
Other rooms in the house are suddenly very dark. The OUT cable carries power to the next ceiling rose, and that rose could connect to another one, and another, and so on.
Another possibility is that the OUT live wire is somehow connected to the switched live. Other rooms only work when the switch is on in this room. Useless and annoying.
Remember - Cables to other ceiling roses must be connected, otherwise other lights in the house will not work.