I watched a short video where it said most simple it is when a magnetic field effects the flow of electrons and makes it more charged on side than the other producing a voltage.

He explained that there a various types of hall effects but this one was most simple one to explain.

Please explain for a layman. 

Maybe you should provide a link to the video. And say what part of the explanation you don’t understand. (There is no point someone here giving the same explanation. )

5 hours ago, Achilles said:

I watched a short video where it said most simple it is when a magnetic field effects the flow of electrons

 

Do you understand how and why a magentic field affects the flow of electrons?

It is called the Lorenz force.

 

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magfor.html