Definition - What does Ion mean?
An ion is an atom or group of atoms (molecule) whose number of electrons is not equal to the number of protons. An ion is a charged particle due to the unbalanced electron/proton numbers —more protons than electrons leads to a positive charge (anion), whereas more electrons than protons leads to a negative charge (cation).
Techopedia explains Ion
An atom or molecule where electron/proton ratio is not maintained as 1:1 is called an ion. A neutral molecule or atom can be ionized in a number of ways to change its physical and chemical behavior, such as chemical reaction or the loss or gain of electrons. The phenomenon of diodes, which constitutes almost every electronic switch, depend on charged particles or ions. Ions serve in everyday appliances and are a very important part of the function of many electronics. Important devices such as cell phones, batteries, light bulbs, display screens, TVs, microwave ovens and motors make use of ions.