Speed is the ratio of the distance traveled over the time taken to travel. It gives us an idea of how fast an object is moving. It is a scalar quantity. That is, it only has a magnitude but no direction. Velocity is the ratio of displacement and the time taken for this motion. It gives us an idea of how fast the object is changing its position. Velocity is a vector quantity and has both magnitude and direction. 

Speed and velocity both represent a way to measure the change in position of an object relative to time. In fact, for a straight line motion, the speed and velocity of an object are the same (since distance and displacement will be the same). Speed and velocity are measured in the same units: meters per second or m/s. 

Hope this helps. 

How are velocity and acceleration similar?

There are a number of similarities and differences between velocity and acceleration. 

Both velocity and acceleration help us describe the motion of objects. 

Both velocity and acceleration are rates of changes of something with respect to time. While velocity is the rate of change of position, the acceleration is the rate of change of velocity.

or, velocity, v = delta x/delta t and acceleration, a = delta v/delta t

Both velocity and acceleration have a time component. They measure a change taking place over a finite time interval.

Both acceleration and velocity are vector quantities. This means that they are described in terms of magnitude and direction. In comparison, speed is a scalar quantity and is described by its magnitude only, without any reference to direction. 

Both velocity and acceleration can be zero during a motion. Circular motion represents a scenario with zero velocity (for every completed circle), while motion with constant velocity will have zero acceleration.

Hope this helps.