Amps (ampere) is a unit of electric current, or amount of electric charge per second. The ampere is an SI base unit, and is named after Andre-Marie Ampere, one of the main discoverers of electromagnetism. It is the measurement of the number of electrons passing through a given point in one second intervals. Around six quintillion (6 followed by 18 zero's) electrons passing through a given point each second constitutes one amp.
Note: Since electrons have negative charge, they flow in the opposite direction of the current.