That is a moldboard plow, some call it a turning plow, depends on where in the country yall from.
It turns the ground over to bury the leftover from the previous years crop, like corn stubble or sod/leaves etc.
It makes the soil loose,and easily worked into a fine seed bed
The ones that throw the dirt both ways are called a middle buster.
They are good for making a furrow to plant 'taters or digging 'taters after they have grown.
They tend to go too deep for planting shallow seeded crops
Also could be used to plant tree seedlings.