What is a switchboard or switch box?
A switchboard or switch box is the box at the front of your house which contains the necessary safety switches, circuit breakers (or MCBs) or fuses. This is the central point from which all of the circuits in your house are arranged, and the point from which they are connected to your electricity meter - which in turn is connected to the mains power.
Where are switchboards located?
Your switchboard and power meter might not be in the same place - because your electricity meter needs to be in a position where meter readers (people employed to read meters) can get at them, the power meter is likely to be at the front of your house even if your switchboard isn't. On rare occasions - like in apartment buildings with limited public access - your switchboard and power meter might be combined, although in that case there will be sub-distribution boards in the individual apartments.
If your switchboard isn't located at the front of your house near your power meter, it may be in a small cabinet in a hallway or cupboard somewhere.
Modern domestic switchboards are designed (or should be designed) to allow for expansion. A popular style of construction is what's known as the DIN-rail box.
Originally a European standard, DIN-mounting has become almost universal. Miniature circuit breakers (MCBs) are generally of the DIN-rail mounting type. They are clipped on to the rail and blank panels are clipped on as well, so that there are no spaces to get fingers in.
If you wanted to put in some more power points, this would normally be done by putting in some more wiring from an existing point. A circuit with a 16 amp circuit breaker, though, is not allowed to have more than 20 power points (GPOs) attached to it. For this reason it's a good idea to plan ahead and make sure there's room for another circuit breaker in the switchboard.
Don’t be too sure that your electrician necessarily pays attention to this - you need to satisfy yourself by asking the question of your tradesperson, especially if you think there's a high chance you'll be upgrading your fittings in future.
Providing that you're using a DIN-rail box, replacing an MCB or adding more for additional wiring runs is a straightforward task.