The incoming service:

That would then feed a distribution panel I think the left terminal strip is the neutral & the right ground [earth] the 2 phases are running down the middle:

With some breakers to install:

2 phase connects to both busbars for a stove or dryer or waterheater usually dedicated circuits...

a single phase for lighting & other small appliances may have several outlets connected to the same breaker

Receptacles have a similar configuration, the round pin is always earth & the slightly wider flat blade being neutral, the screws are always color coded green=earth, silver=neutral, brass=hot this is the basic convention for 120vac, the higher power 220vac can be found in many configurations 3 wire [2 out of phase hot &a ground] being the most common.

More expensive GFI's [ground fault interupters] being required anywhere water is in close proxmity, say a bath for instance, generally there are no protection devices after the distribution panel for residential installations.

I won't even begin to describe the diviations to be found in industrial installations.