$(a)$ Write differences between speed and velocity.
$(b)$ The speed of a moving object is $x \ m \ s^{-1}$. Its velocity is $y \ m \ s^{-1}$. What is the similarity observed?

(N/A) Speed is the distance travelled per unit time,whereas velocity is the displacement per unit time.
Speed is a scalar quantity,while velocity is a vector quantity.
Speed can never be zero for a moving object,whereas velocity can be zero if the displacement is zero.
$(b)$ Both speed and velocity have the same $SI$ units,which is $m \ s^{-1}$.