Tractors come in four different possible arrangements; two-wheel drive, front wheel assist two-wheel drive, four-wheel drive (often with articulated steering), or track tractors (with either two or four powered rubber tracks).
Classic farm tractor was originally an open vehicle, with two enormous torque wheels on an slightly below and behind a single driver’s seat generally located in the center of the vehicle, and the engine in front of the driver, and two smaller wheels below the engine which are used for steering. The fundamental design hasn’t been changed since its creation however slight modifications have been added. Enclosed cabs on modern models are most common as well as safety precautions (interior warning lights, rear roll-over attachments, and driving lights) and comfort arrangements (seat cushions, steering wheels, levers, cup holders, etc,).
Crawler or Caterpillar type of tracked tractors became popular in the early nineteen hundreds, due to superior floatation and traction. These were usually maneuvered through the use of turning brake pedals and separate track clutches operated by levers rather than a steering wheel.
Four-wheel drive tractors began to show presence in the mid nineteen hundreds. Some four-wheel drive tractors have two large wheels and two small wheels typical of small tractors, while some have four large wheels. The larger tractors are typically an articulated center-hinged design steered by hydraulic cylinders that move the forward power unit while the trailing unit is not steered separately.