reduction

A reduction reaction is any reaction in which the oxidation number of a formula unit reduces. For example, if an ion reduces in charge after a reaction (e.g. $\mathrm{Fe}{}^{3+}$ to $\mathrm{Fe}{}^{2+}$), then it has oxidized.

Standard conditions

The standard conditions for reduction potential ($E^{\circ }$/${\xi }^{\circ }$) is $1\mathrm{M}$ concentrations of aqueous ions (or $1\mathrm{atm}$ pressure)