Electrolysis is a phenomenon where dissolved or molten electrolytes (ionic compounds) split-up into other element/ compound substance, due to application of external voltage. Electrolysis has many applications, especially industries.
Electrolysis is a phenomenon, where, on dissolved or molten electrolytes (ionic compounds), voltage is applied from an external source (through electrodes); components of the compounds, i.e. the cations (+ve charged particles) and anions (-ve charged particles) move through the fluid, along an electric field, according to the voltage gradient ((i.e. to neutralize the electrodes. Cations (+) move towards the cathode (the electrode where negative charge is being applied from the exterior) and anions (-) move towards the anode (the electrode where positive charge is being applied from the exterior))). When an ion particle reaches the electrode, it no more becomes neutralized by its counter ion, but by the incoming (at the cathode) or outgoing (at the anode) electrons. As a result, the ion goes through a chemical change into a neutral species, ("released" or "discharged") and usually does not go back to the initial state. (However, from more than one cation or more than one anion, which one will be released depends upon various factors like discharge potential, overvoltages etc.; those again depends upon the ions, the materials used to make the electrode, etc.)
Electrolysis has many applications, including electroplating, element extraction and purification.
However, there is a very common example of electrolysis in day-to-day life, i.e. recharging a rechargeable (secondary) battery cell, which is the reverse reaction of electrochemical cell (battery), where the normal cathode of a battery cell (+ve out) is forcefully converted into an anode (+ve in), and normal anode of a battery cell (-ve out) is forcefully converted into a cathode (-ve in).
