Charge and current
According to the prevailing thought fitting all models, an electric current is a flow of charged particles. Nobody can be certain of structure at these scales but such a model works incredibly well. I will expand on this understanding for the sake of simplicity and move from one electron to the cosmic web as marvel at how electricity is far and away the dominant phenomenon in the universe........ The Electric Universe!
In metal conductors lets consider the charged particles free electrons.
The electrons are free to move from one ion to another and a net flow of these electrons in one direction is an electric current.
if we don't get technical about the definition of energy the we could say a build up of charge is a store of energy, but more correctly potential work, or a difference in charge. It's this (a voltage such as a cell or battery) that is required to facilitate the creation of a circuit to cause the free electrons to move in one direction.
Electromagnetism
Everything is to some small extent magnetizable, and everything is to some small extent able to be electrostatically charged, not just metals. Electric current causes magnetic fields and magnetic fields can induce electric current, but it's not a chicken or the egg situation because no magnetic field is known to be proven able to form without current, with the possible exception of point charges like the electrons themselves which have their own tiny fields, and by model theorized as a monopole point charge, so chances are that explaination is not the whole story, its just as far as we have gotten. Even remnant magnetism in iron bars seems to have originally needed electric current to form.
Charge
Electrons are considered negatively charged particles and they transfer electrical energy from a cell, through conducting a medium, as an electric current.
Charge is measured in coulombs, C.
The charge of an electron is 1.6 x 10-19 C.
In other words, it takes 6,250,000,000,000,000,000 electrons to make up 1 coulomb of charge.
A coulomb of charge is just a very large group of electrons by this reckoning.
The relationship between current I and quantity of charge Q
An electric current is a flow of charged particles.
The size of an electric current is the rate of flow of charge.
Current I = 
I = 
This is often remembered as:
Quantity of charge Q = current I x time t
Q = It
Where:
Q = quantity of charge in coulombs, C
I = current in amperes, A
t = time in seconds, s
| I = | I = Q ÷ t |
| Q = It | Q = I x t |
| t = | t = Q ÷ I |
Those are the basics. Current can also flow through the air or gasses, such as the cathode ray tube of an old TV set. More commonly these days we see fluorescent lights the current flows along an ionized gas such as Argon, which we could then consider a plasma, and current passing through it would make it glow brightly.
In electric welding, the torch conducts electric current to the electrode and carries the shielding gas to the arc zone of the welding arc. (In gas welding, the torch serves to adjust the mixture of gases and to guide the welding flame.)
This is more or less the same situation with Neon lights.
Those are the basics. Current can also flow through the atmosphere and Magnetosphere/ Ionosphere and indeed this is what causes the AURORAS near the poles. Lightning is an example of charge equalization in the lower atmosphere but the notion that water droplets building up the charge is wrong because we have measured the voltage during thunderstorms and it exists before the strike, in fact its likely that thunderstorm clouds are a CONSEQUENCE OF rather than THE CAUSE OF electrical phenomena in the atmosphere.
Above: Red sprites are a testament to this charge separation hypothesis being an upwards discharge further into space and the barrier of the earth/sun electrical environment. See this link:
I have covered the suns electrical environment in great detail here in this post:
Ionized plasma is the most abundant state of matter in the universe by some way. It most likely makes up over 99% of matter in the universe. On earth solids, liquids and gasses are by far the most abundant while plasma (the fourth state of matter) is only present as fire, lightning, in the ionosphere and various places such as the neon lights we covered earlier. Ionized materials have to some extent the electrons separated from the nucleus of the atoms creating ions. It cannot be thought of as an ideal gas operating as a mysteriously magnetised fluid, especially in space where being contained by its own fields in micro gravity and given enough room for phenomena (which are scalable) to compound give it a life of its own. For these reasons and others magneto-hydrodynamic equations fall short of understanding the dynamics of real observed plasma physics.
Plasma on earth: Fire, lightning, neon lights, arc welding, the ionosphere/ magnetosphere.
Plasma in the solar system: Most of the sun and all stars are plasma or condensed matter. The entire heliosphere stretching far outside the planetary orbits is the suns plasma environment.
Plasma is the interstellar medium and more than likely makes up the 'Cosmic Web'.
It is in dark or current mode until its carrying enough current (depending on the material) to enter glow mode. Arc mode is when its discharging with the intensity of lightning or the solar photosphere, or (of course) arc welding.
Plasma Cosmology seeks to expand our understanding since it's critically lacking at the moment. Unlike on earth (unless we look inside the SAFIRE Project as in the pic below the underlying clip) those ions and electrons self organize in the near vacuum of space, creating the most incredible and beautiful structures sometimes spanning many light years.
A lab version of the plasma magnetic entities
quite simelar to how they might appear at
the galactic centers is demonstrated below.
A lab version of the plasma magnetic entities
quite simelar to how they might appear at
the stellar scale is demonstrated below.
Regarding the beautiful images above: Self organizing plasmas in the SAFIRE reactor chamber in lab on earth. On earth we normally only think of plasma in terms of gas laws but in the radiation environment in space its another story since electrons are knocked from ions all the time creating plasma out of hydrogen and other gases. Plasmas that are even 1% ionized allow charge movement (often an excellent conductor even at such levels).
Below: The self organizing twisted ropes of cosmic ionized plasma when a current flows through it.
Plasma is THE INTERSTELLAR MEDIUM and all the pervasive electric and magnetic fields in space are directly caused this way. These are electrodynamic basics and that role is severely under appreciated in cosmology today.
They are explained them all in reasonably accessible detail here:
❇️ Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of electric charge: positive and negative (commonly carried by protons and electrons respectively). Like charges repel each other and unlike charges attract each other. An object with an absence of net charge is referred to as neutral. Early knowledge of how charged substances interact is now called classical electrodynamics, and is still accurate but physics is losing its way asking for solutions of problems that do not require consideration of quantum effects, a statistical and probabilistic approach, and reletivity, which is is a load of nonsense put forward by Einstein before falling out of favour with most serious scientists except the public funding dinosaurs of LAMBDA-CDM hanging around the astrophysics establishment.
