Question

1) what is uniform circular motion?

2) what is non uniform circular motion?

Answer 1

Uniform circular motion can be described as the motion of an object in a circle at a constant speed. As an object moves in a circle, it is constantly changing its direction. At all instances, the object is moving tangent to the circle. Since the direction of the velocity vector is the same as the direction of the object's motion, the velocity vector is directed tangent to the circle as well.
Example :Orbiting of satellites around the earth.

In non-uniform circular motion an object is moving in a circular path with a varying speed. Since the speed is changing, there is tangential acceleration in addition to normal acceleration.

In non-uniform circular motion the net acceleration (a) is along direction of Δv which is directed inside circle but does not pass through its center . The net acceleration may be resolved into two components: tangential acceleration and normal acceleration also known as the centripetal or radial acceleration.

Unlike tangential acceleration, centripetal acceleration is present in both uniform and non-uniform circular motion.

Hope this helps :)