Drude Model electrons (shown here in blue) constantly bounce among heavier, stationary crystal ions (shown in red).

We know that current and voltage are a consequence of electrical charges. The charge is one, and the consequences are two. How can this be. In fact, the relationship between voltage and current strength, expressed through Ohm's law, is through a coefficient called resistance. Ohm's law says that the current is directly proportional to the voltage, and the reverse to the resistance. In fact, this indicates that the voltage and current are the same phenomenon, but represented through a "geometric" coefficient. Why did I call resistance a geometric coefficient? Because its size is determined by the size of the element. Conditionally, resistance is throughput, per unit time. Like a pipe for water. Increase the tube twice the water will be the same you two times. But you can increase the pressure (if only the pipe has withstood), which will increase the speed and at a constant size, the pipes increase the water flow through the cross section per unit time.

Let's return to electricity. By analogy with water, tension is pressure. Most likely, therefore, it is called the potential difference. If there is a potential difference, then there will be pressure in the direction of a smaller potential. Pressure is a consequence of the potential difference.
Voltage, when the circuit is closed, creates a pressure that pushes electricity along the path, from a larger potential to a smaller one until they equalize. Electricity does not disappear, there just comes a time when there is no difference in potentials.
How to create a difference in potentials, I hope you know this and the chemical method - batteries, and the mechanical method - the static potential, and with the help of magnets, in so-called "generators".
Electric current is the amount of electricity passing through the cross section per unit time. If there was no resistance to the pressure created by the potential difference, then the electricity instantly equaled, on the two potentials, and the difference would disappear. But this can not be, because the very existence of a conductor, in any case, implies the presence of resistance. And all these tales of superconductivity, do not correspond to reality. Yes, the conductivity becomes very low and there is practically no resistance. But it is still there, it can not be, it's just very small and the devices are not able to show it. The resistance of the same devices does not change, because they simply do not notice superconductivity, and they give out the wrong data.
Because of the difference in potentials, pressure pushes electricity through the conductor, in order to equalize the potentials. If one potential is equal to 1, and the second is zero, then it is logical to assume that the motion will stop when both potentials become 0.5. If the second potential is -1. That movement will stop when both potentials are 0.
When the voltage is doubled, at a constant current source strength, the amount of current will increase two times per unit of time all through the same cross section. This indicates the speed of electricity transfer. Do not forget the analogy, with the pipe, when the pipe does not withstand pressure and bursts. In the case of electricity, the conductor burns out - bursts. More current, more heat and everything - finish.

[Ohm's law in Georg Ohm's lab book.](By Lukas Mezger - Own work, CC BY-SA 4.0, Link)
Now let's use the analogy of Ohm's law using pressure.
The current strength (I) is the volume (V) of the passing fluid per unit time. The voltage (E) is the pressure (P). Resistance (R) is the cross-sectional area (S).
I = E / R

V = P / S

An interesting conclusion suggests that the speed of electricity is not constant. And depends on the voltage, with constant other parameters. By increasing the voltage, we can get more current, therefore, do more work.

By Waveguide2 (talk) (Transferred byNk/Originally uploaded by Waveguide2) - I created this work entirely by myself. (Originally uploaded on en.wikipedia), Public Domain, Link

By Rafaelgarcia - Electrona in crystallo fluentia.png. Uploader believes this faithful SVG reproduction constitutes a mere mechanical conversion between formats and as such cannot be considered a derivative work. Uploader accordingly believes uploader has no share in the copyright of this file., CC BY-SA 3.0, Link