A carcase is the basic framework of a cabinet. In a simple floor cabinet, it's generally made from whiteboard (that is, white melamine particleboard) and consists of a back, base, two ends, and two rails.

The rails are used to fix the underside of the bench top to the carcase.

Sometimes the front rail is turned on edge (as shown here in the left hand cabinet), rather than on flat, especially when a sink or hot plate is mounted above.

This avoids the problem of the installer having to cut away part of the rail to allow for the deep inset.

There are various ways of attaching the back of the carcase to the end panels.

An external back is cut to the outside width of the cabinet and is fixed to the rear edge of the two end panels.

An internal back is cut to the inside width of the cabinet and fixed through the sides of the end panels.

There are other ways of fixing a back panel, although these aren't used much for kitchen and bathroom cabinets.

One method is to cut a groove in the end panels and insert a rebated back.

This is a traditional cabinetmaking technique, and allows the joint to be glued without the need for nails or screws.

Another method is to insert a hardboard or thin MDF back into a groove in the end panels, and fix the rear rail behind it, turned on edge.

This is called a rail and panel back.

Whatever the shape or size of the cabinet, most carcases have the same basic structure.

This corner base unit, for example, faces in two different directions, but it still has a base, two ends, and in this case, two backs and two front rails.

In the next lesson, we'll look at the process of assembling the panels and fixing them in position with screws, nails or staples.