Not quite.

Average velocity = (d_{f}- d_{i})/(t_{f}- t_{i})

Instantaneous velocity is the velocity at one point.

It is what you get if pick your t_{i}and t_{f}at the same time.

You can't really do that since you'd be dividing by zero, but you can make the one approach the other as close as you want.

This is what you do when you calculate a limit.