Define the Elements of a galvanic cell?

We will treat a galvanic cell as a system. The cell has two metal wires called terminals that pass through the system boundary. Within the cell are phases that can conduct an electric current and are collectively called electrical conductors. Each terminal is attached to an electron conductor that is usually a metal, but might also be graphite or a semiconductor.

Figure: A galvanic cell without liquid junction.

Each electron conductor is in contact with an ionic conductor, usually an electrolyte solution, through which ions but not electrons can move. Both of the electron conductors can be in contact with the same ionic conductor; or they can be in contact with separate ionic conductors, in which case the ionic conductors contact one another at a liquid junction.