How Exposure Works

To understand exposure in photographical terms, EV is probably the single most important number you will have to understand, to understand the theory behind the art of photography. This goes from your tiniest, least significant compact camera, to your cock-on-the-table style medium format camera with a digital back. [via photocritic.org]

The photocritic explains the technical and non-technical parts of the EV setting on cameras and best of all, explains what that EV number is used for. A must read.