576p is the shorthand name for a video display resolution. The p stands for progressive scan, i.e. non-interlaced, the 576 for a vertical resolution of 576 lines, usually with a horizontal resolution of 720 or 704 pixels. The frame rate can be given explicitly after the letter.
In other words, standard-definition television (SDTV) with a frame rate of 25 hertz. It can be used on analog PAL or SECAM systems (as a 576i signal with both interlaced fields corresponding to a unique frame). PALplus supports it via a "movie" mode signal flag. It can also be transported by both major digital television formats, ATSC and DVB and on DVD.
With doubled temporal resolution, 576p50 is considered enhanced-definition television (EDTV). In some countries, such as Australia, the 576p resolution standard is technically considered high-definition and was in use by the Special Broadcasting Service (SBS TV) (16÷9 the format has aspect ratio 1024:576), eventually replaced by 720p for its high-definition subchannel. The Seven Network initially used 576p for its high-definition subchannel, which now uses 1080i instead.