In general, there are few true differences between a cupboard and a cabinet. The two terms are almost synonymous, though some people consider the difference between them to be the presence of shelves within the unit: cupboards have shelves, while cabinets do not. This is a loose distinction, however, and some people consider a more accurate distinction to be the primary use of the item: cabinets are a broad term for storage units, while cupboards are used specifically for displaying cups, plates, and other flatware by using doors with glass panes.
A cupboard and a cabinet can be a freestanding unit or a wall-mounted unit, and very often no physical differences are apparent between the two. Many people will label a cupboard as a cabinet with a wood and glass door that allows a person to see into the unit to view the contents; some cupboards even feature no doors at all, revealing the plates and cups within. A cabinet can be more multi-purpose, and storing items in a cabinet can be done with or without shelves. Pots and pans, for example, are often stored in lower cabinets beneath a countertop.