Magnetism and Electromagnetism.
Magnets have two poles: one north and the other south pole, Two north poles repel each other, as do two south poles. North and south poles attract each other. Magnetic fields is defined as a physical field established between poles. Its intensity and direction determine the forces of attraction or repulsion existing between two magnets. Generators use a conductor in the shape of a coil to form a magnetic field created by the flow of current through the coil (conductor). When more turns are added to the coil, with the same current, then it will produces larger and larger magnetic fields. When the coil is operated in air, the magnetic field direction, shape, and intensity depends on the number of turns in the coil, the size of the coil, and the direction of electric current flow in the coil winding. The flux produced is basically divided into two types. One is the effective flux that links the entire coil and does the useful work, and the other is the leakage flux which is more localized effect and does no useful work. In fact, the leakage flux creates additional losses that make the coil less efficient, electromagnetically speaking. To use as much of the flux produced in a coil as effectively as possible, highly magnetically permeable materials- basically, ferromagnetic materials are used to capture and direct the flux so that the amount of leakage flux is minimized. This allows the coil to do more useful work and keeps losses to a minimum. iron in various derivatives is by far the most widely used material because it has all the magnetic characteristics required, is structurally suitable, and cost-effective. When an "iron" core is used within the coil, and current is flowing, the magnetic field produced is shaped effectively and the iron core essentially becomes a north-south magnet in the process. This is why rotor forgings and stator cores of generators are made of iron. The iron allows the principles to become a reality and is one of the reasons generators can be built to at least 98.5% efficiency.
Electricity flow in positive or negative chargers. Electricity can flow in electrically conducting elements, or it can flow within gases or in clouds of ions in space.