[Bromskloss]

> Voltage is just simply the effort exerted by electromagnetic field on neighboring electrons.

That sounds like you are talking about the _electric field_, which is a vector field. Charged particles feel a force in the direction that the electric field is pointing. This is analogous to the gravitational force field (a vector field pointing towards the ground) and how objects with mass feel a force in this direction.

The electric field has a _potential_ [0] (called the _electric potential_), which is a scalar field. This is analogous to gravitational potential, which coincides with height.

_Voltage_ is the difference between the electric potentials of two points, for example the two leads of a resistor (or other circuit element).

[0] https://en.wikipedia.org/wiki/Scalar_potential