Electric Field And Electro static potential

Electric field is a vector quantity.It will determine how much amount of force getting for a unit charge due a Q amount of charge in space. And it is a vector quantity also. We need x,y,z vector components to determine the E vector. But electro static potential is the Potential energy of a charge to bring from infinity to a point in space.

Interesting thing, it is constant for a particular distance surface from the charge. What ever way we reach to that point the Electrostatic potential will be constant.
Electrostatic potential depends only on the radial distance from the charge.So depends only on one quantity

And from ELECTROSTATIC POTENTIAL we can determine the value of E which is vector (depending 3 components x,y,z)


These calculations and derivation I have studied in Btech days itself.But I didn't get the advantage of these ELETROSTATIC potential.

Gradient chapter:http://www.nptel.iitm.ac.in/video.php?courseId=1009&sub=Electrical&sem=Semester%204