Normal Map node Or Bump Map node.

What is the difference between these two nodes? I am confused, are they same? I have seen some tutors using either of them connecting it to a normal map and getting almost same effect.

What am I missing?

A normal map encodes more information about the direction the surface normal is facing at any given point compared to a bump map.

You get a better quality representation of the surface texture as a result (as long as you use it properly).