can you explain me Instantaneous Velocity in simplest form?
The average velocity over a time interval is the distance traveled divided by the time interval. The instantaneous velocity is the limiting case, where the time interval approaches zero.
Instantaneous velocity can be thought of as "[the vector quantity with magnitude] what your speedometer reads right now, together with the direction your car is pointing".
On a displacement-vs-time graph, you can visualize krab's definitions as
average-velocity="the slope of a line-segment with endpoints at the start and end of the time-interval of interest"
instantaneous-velocity="the slope of the tangent-line at the instant of interest"
It's good to remember these prepositional phrases
average-velocity over a specific time-interval (you need to specify two times [better: two events])
instantaneous-velocity at a specific instant (you need to specify one time [better: one event])
Separate names with a comma.