Both garden tillers and cultivators are rotary tools used to aerate and stir soil. The biggest difference between garden tillers and cultivators is their size; small cultivators are often referred to as garden tillers. In most cases, the term "cultivator" is used to describe is a relatively large piece of farm equipment designed to prepare fields for planting and help control the growth of weeds between rows of crops. A garden tiller accomplishes the same task but on a smaller scale.

Whether a piece of equipment is called a garden tiller or a cultivator is largely dependent on the manufacturer. Both are involved in the process of killing weeds, digging furrows, and aerating the soil. Garden tillers and cultivators both range widely in size, from small hand-operated tools to large gasoline-powered tractors, although larger equipment tends to be called a cultivator.

Garden tillers and cultivators usually have between one and five long or short, curved or straight, pointed or flattened tines. These serve to break up the soil around plants, keeping it loose and friable. Gasoline-powered tillers and cultivators are very common, although electric tools are also available. Most garden tillers are designed to be pushed by a user walking behind it; the engine turns the tines, making it easier to break up compact soil. Larger garden tillers and cultivators are made to be attached to a tractor, and do not have their own power source.

Tillers are often categorized by where the engine sits in relation to the tines. A front-tine tiller, in which the tines sit slightly ahead of the engine, are some of the most popular. The user must push the tiller forward, and maneuver the tines into the ground, so this type of tiller can be more difficult to use. Some front-tine tillers are as small as 8 inches (about 20.32 cm) in diameter, however, and will fit between rows of growing plants. Care usually must be taken when using these small tillers since cultivators not to go so deep as to damage the roots.

Mid-tine tillers, which are often grouped with front-tines, have the engine positioned over the tines. These are often considered easier to use than front-tine tillers, since they are propelled by the tines. They're also often more expensive than front-tine tillers.

Rear-tine tillers tend to be larger and more complicated than other types of cultivators. They are often more powerful, and have wheels separate from the tines that pull the machine forward. This type of tiller is relatively easy to use, and good for hard-packed ground.

Some small hand tools are also called cultivators. These tools consist of a series of three or four spiked rotary heads connected to a long pole. The small size of these cultivators make them ideal for use in between rows of plants. These tools are also easier to control than gasoline-powered tillers or cultivators, which could damage plants. Hand cultivators often require more strength and effort to use, however, and are best used in relatively small areas.