The tractor was probably the first replacement for the horse, oxen drawn plow (plough) on the farm. Before that man had to open the earth literally by hand, but now there was a machine that could do it without him having to push.
The threshing of cerials was already established through the use of the steam engine, but those heavy engines were not able to go over heavy soils.
Massey Ferguson reveloutionised farming with his tractor machines and nothing much has change since in the design shape.
In Russia and the United states, the tractor machines are a different in shape and tracked versions have been produced.They of course are also much larger.
Modern machines meanwhile have all the latest comforts from heating to swivel chairs and double driving cabs, lighting inside and out. Meaning that the machines can work day and night.