The modified velocity gained by the accelerating electrons in uniform electric field inside the conductor is called drift velocity.
The average velocity, acquired by free electrons along the length of a metallic conductor, due to existing electric field is called drift velocity.
Let n be the number density of free electrons in a conductor of length l and area of cross-section ‘A’.
Total charge in the conductor, Q=Ne
=(n Al) e
Time taken at average velocity Vd is t = 1/vd