An ion is any atom that bears a positive or negative electrical charge. Positively charged ions are called cations; negatively charged ions, anions. The imbalance between quantities of electrons and protons gives rise to electron movement both within and between atoms. Electronics is, therefore, about the flowing motion produced by an electric charge.
A duct is pretty much any channel such as a tube, canal, pipe, or conduit by which a fluid such as water or gas, or a particle may be conveyed. The act of conveying or channeling by means of a duct or ducts gives rise to certain essential terms that we use to understand and make use of electricity. In this treatment we will consider the process by which an electrical charge is inducted and conducted.