Voltage:

Voltage, emf (electromotive force), or potential difference, is defined as the pressure or force which causes electrons to move in a conductor.  Within electrical formulas and equations, you will look voltage symbolized along with a capital E, although on laboratory equipment or schematic diagrams, a voltage is frequently represented along with a capital V.

Current:

Electron current, or amperage, is defined as the movement of free electrons by a conductor. Within electrical formulas, current is symbolized along with a capital I, although in the laboratory or on schematic diagrams, it is general to use a capital A to denote amperage or amps (amps).