What's the difference between a normal & a dwarf planet?

As many of you may ask, what is actually the difference between a normal planet and dwarf planets??
Here I will tell you that it is a matter of size, with dwarf planets being smaller..

Then you might ask, how big must a planet be to be categorized 'regular' or 'normal' and not 'dwarf??
It's not just the size that matters, but it is also based on different facts.. For example, the history of the object in the solar-system & other properties of the object.

But both, regular & dwarf planets, need to be big enough so that their gravity can form them into a shape of spheres. This means, we can't even call normal asteroids, which are irregular in shape, a dwarf planet. Here, normal planets also have a greater gravity force than dwarf planets.