How does uniform linear motion differ from uniform circular motion?

Uniform linear motion is motion with a constant velocity (zero acceleration) and uniform circular motion is motion with constant speed and constant centripetal acceleration (non zero).

Uniform linear motion is motion with a constant velocity (zero acceleration). Uniform is motion with constant speed and constant centripetal (non zero).

Uniform circular motion is motion where a centripetal acceleration always acts towards the centre and is always perpendicular to the velocity of the object. In order for the speed to be constant, the acceleration must be a non zero value.

Some diagrams of circular motion

Conversely uniform linear motion is motion that typically has no acceleration and is traveling at constant velocity.

Uniform circular motion can also be represented by a simple harmonic oscillator. When viewed from the side and measuring the acceleration on the X axis, the acceleration will produce a sine curve.