I, current, is the amount of electricity flow through a designated plane within a unit of time.

If we make a hypothetical section of a wire in a circuit, within 1 second, there’s gonna be X electrons pass by.
Each electron takes 1.602 x 10^-19 coulombs (C), which you could take as the “magnitude of electron charge”.
X, divided by time, is the “I”. Measurement of I is C/s, also known as A (Ampere).

V, voltage, is the discrepancy between 2 designated point of space, of the energy stored.

Think about height(H), energy of gravitation is stored in the heights of objects. E = H * g * m, where g is gravitational acceleration, and m is mass.
Electronic forces, calculated by F = k * |q * q’| / d *d, is very close to formula of Universal Gravitation: F = G * (m * m’) / d *d, the “d” in both formula stands for distance. The “q”, is the magnitude of the charges of the two particles.
When objects fall, the height decreases, but acceleration stay still. However, if it is held by a “upward resistant force”, the acceleration could goes down to zero. It is the same as electrons pass a material with resistance being R. The acceleration is 0, the speed is stable. In this example, we feel like the “upward resistant force” stands as a substitution of R.
- “upward resistant force” = m * g

It is similar to gravitational field strength, which could be understood as g, “gravitational acceleration”; this formula is correct only when E stays still, which is the situation of our circuits.
- “upward resistant force” = m * g
- R = E * q
- What’s the relation between E and V or I? Well, as we compare E with g, then the role that stores energy, being h in the case of gravity, is V, the physical quantity describing the energy of a certain position in a field.
- like W = gmh, where W stands for Energy, it is also true that W = V*q.

As we compare Resistance with “upward resistant force”, R is to describe how a material, with its shape, together with temperature and other conditions, restrains the current.