The p stands for progressive scan, i.e. non-interlaced, the 576 for a vertical resolution of 576 pixels (the frame rate can be given explicitly after the letter).
[2][3] ITU-R Recommendation BT.1358 allows the following resolutions, coded as R'G'B' or YCBCR, with timings compatible with BT.656:[4][2][3] 576p is considered standard definition for PAL regions.
It can be transported by both major digital television formats (ATSC and DVB) and on DVD-Video (if limited to 25 fps).
This resolution can be also named as PAL, for example in the context home video[6][7] or gaming consoles,[8][9] because of its relation with the analog color system using a similar number of scanlines.
With doubled temporal resolution, 576p50 is considered enhanced-definition television (EDTV), regardless of the image being scaled the same way as an interlaced frame.