576i is a
standard-definition video mode originally used for
broadcast television in most countries of the world where the
utility frequency for electric power distribution is 50 Hz. Because of its close association with the colour encoding system, it is often referred to as simply
PAL or PAL/
SECAM when compared to its 60 Hz (typically, see
PAL-M)
NTSC-colour-encoded counterpart,
480i. In digital applications it is usually referred to as "576i"; in analogue contexts it is often called "
625 lines", and the aspect ratio is usually 4:3 in analogue transmission and 16:9 in
digital transmission.