Can anyone help clarify what these ‘boxes’ are

The larger one will be hinged cover with all the house circuit breakers in - like a fuseboard but with sensitive trip switches for the whole house and various circuits, like ground floor sockets, ground floor lights, upstairs sockets, kitchen etc.

There will be lots of the small square ones round the house and they are used to access wiring. Unlike the UK wires are threaded round the house using plastic "hosing", so for example if you add a satellite dish on the top floor the connection for this will be passed neatly down through the house to reach an outlet near the tv.

It is a good idea to see which circuit breaker controls what, and label them, so if a breaker trips you know where to look for the cause of the trouble.

The bottom one is the cover to your fuse box.

Put you fingers on the left hand side of the cover push in ( to the right ) & pull towards you at the same time. It should then swing open.

The top one is a an access cover to the internal house wiring.

Peter thanks for confirming and good suggestion 

Roland

Thanks for the reply 

Another tip re the electric & tripping off & the new smart meters.

If your electric trips off you don't need to go to the smart meter & reset your electric.

Turn off all the trip switches in the house wait about 30 seconds & turn all the trip switches back on again. 

This will re set the smart meter & you electric will come back on without having to go to the smart meter.