The differences between a tiller and a cultivator lie in the purpose of each and the strength of the construction of the machine. A tiller features a powerful engine that digs through the dirt to break up tough clumps of earth and clay, while a cultivator is less strong and churns soil and fertilizer together to prepare the earth for planting and help reduce the instance of weeds.
Tillers come in front-tine and rear-tine models. Front-tine tillers are often best for digging in soft to medium dirt and preparing new rows for planting in a field. Rear-tine tillers are sturdier than their front-tine counterparts and can dig out new fields from tough soil and clumped clay or earth. Rear-tine models also deal far better with rocks and similar obstructions in the soil, dragging these out to help prepare new areas for future cultivation.
Cultivators feature designs that amply mix soil and fertilizer or similar amendments together, and the blades on cultivators typically do not cut into medium or hard dirt the way that the tines on tillers can. Cultivators aerate the soil and help evenly distribute nutrients, and farmers use them even after plants are in place to help keep the area around the new growths soft and fertile.