720p (720 lines progressive) is a progressive HD signal format with 720 horizontal lines/1280 columns and an aspect ratio (AR) of 16:9, normally known as widescreen HD (1.78:1). All major HD broadcasting standards (such as SMPTE 292M) include a 720p format, which has a resolution of 1280×720.
The number 720 stands for the 720 horizontal scan lines of image display resolution (also known as 720 pixels of vertical resolution). The p stands for progressive scan, i.e. non-interlaced. When broadcast at 60 frames per second, 720p features the highest temporal resolution possible under the ATSC and DVB standards. The term assumes a widescreen aspect ratio of 16:9, thus implying a resolution of 1280×720 px (0.9 megapixels).