Wiring a lamp holder

I'm trying to wire 4 lamps in parallel to use in a custom space.

I have the lamp holders, bulbs and wire. I just need to wire it all up.

I know how to wire in parallel, I just don't know how the wire should be connected to the lamp holder.

Here is a picture of the lamp holder;


1) What are the 4 holes for each terminal for?
2) I know they all can't be used, but which do I use?
3) There are no screws here to attach the wire to, do I need solder for this?

Thanking you

It looks like they're spring terminals. Push a small screwdriver blade into the oblong hole to release the terminal, and place the stripped end of one wire in each round hole. Withdraw the screwdriver and the spring grips the wire.

Thank you TicklyT!

Any idea why there might be two holes for each terminal?

Sorry stupid question! Please ignore