One major difference between disc plough and disc harrow is

The main difference between a disc plough and a disc harrow is their purpose and how they interact with the soil. A disc plough is used to turn over and break up the soil to create furrows for planting crops, while a disc harrow is used to break up clumps of soil, level the ground, and prepare it for planting by chopping up weeds, roots, and plant residue. The disc part of a plough is notched, which helps it to cut through the soil, while the disc part of a harrow is round, which allows it to smooth out the soil surface.