[stefon]

I am just starting off and was wondering if someone could explain to me the difference between velocity and acceleration. Also, what is the relationship between the two?

Thanks
Stefon

[tjb1]

Acceleration is how fast it moves up to speed, Velocity is the speed it moves at.

[Geof]

The precise definitions which you would have learnt in Physics at High School or College is that Velocity is the Speed at which something is moving in a specified Direction. And of course Speed is distance moved per unit of time; feet per minute, miles per hour, meters per second, etc.

Acceleration is the rate of change of speed per unit of time. For instance the acceleration of a free falling body near the surface of the earth is very close to 32 feet per second per second downwards. When you release an object it is travelling at a speed of 32 feet per second after one second and 64 feet per second after two seconds and so on when air resistance is ignored. Actually for a falling body because it is going in a specified direction it is correct to say that its Velocity increase; Velocity is always the combination of Speed and Direction.

[Al_The_Man]

And to add the other maxim, a body at rest tends to stay at rest, a body in motion tends to stay in motion.
IOW, simplified, the effort is usually in getting a body up to the final velocity (acceleration) and effort to return to zero, (deceleration).
In the CNC context, the inertia of the load has a very important effect on motor sizing, and is dependent on the acceptable or desired accel/decel.
Al.