The step after plowing a field is to get the clumps of dirt broken up and smooth the dirt a bit.
The tool used for this is a disk harrow. Tractors usually pull the harrow behind and groom the ground. Sometimes horses are used with the harrow behind and behind that, the farmer.
This first picture is a a field that has been plowed, but not harrowed.
You can see the clods of dirt and that the ground is bumpy from the plow.