Vacuum cleaners were a luxury item until after World War II, when the middle classes began buying them in large quantities. (The fact that wall-to-wall carpet was now standard in most homes was also a factor.) Soon a variety of models and styles emerged, forcing consumers to figure out which kind of vacuum cleaner was right for them.

The most common style is the upright vacuum cleaner, which has the bag mounted on the handle. The whole unit is pushed around the carpet, with the suction intake on the bottom.

Another familiar type is the canister. This has the bag and the motor in a cylinder-shaped unit mounted on wheels, with a hose coming out of it to suck up the dirt. The hose makes the canister vacuum cleaner a little easier to use when it comes to tight spots, though most upright cleaners have optional hose attachments, too.

Some specialized canister vacuums are known as wet vacs or wet/dry vacs and can be used to clean up liquid spills, too.

A variation of the canister cleaner is the backpack vacuum, which has the user wearing the canister portion on his back. This is used almost exclusively in cleaning commercial areas such as offices and schools. Wearing the canister rather than pushing it around on wheels means the worker can cover a lot of ground more quickly.

One modern variation is built-in or central vacuum cleaners. Under this system, a home or office has the vacuum built directly into the walls, with ports in every room. You simply plug a hose into the port and do your vacuuming, the debris taken away to a central container that only needs to be emptied a few times a year. Since the suction unit doesn't have to be portable, it can be stronger than the type used in traditional vacuum cleaners.