720p, also known as HD (high definition), is a display resolution measuring 1280 x 720 pixels. Resolution explains how many pixels a display has in width x height format (the more pixels a display has, the sharper its image quality).
You'll sometimes see displays with a resolution of 1920 x 1080 resolution also called HD, but this is more officially referred to as 1080p or Full HD (FHD).
720p compares favorably to the old Standard Definition (SD), which is usually around 640 x 480. But with 2K and 4K getting more popular, 720p isn't considered very sharp for today's PC monitors, laptops or TVs. If you're buying a monitor or shopping laptops, don't settle for anything less than 1080p.
Common Display Resolutions
|5K||5120 x 2880|
|4K||3840 x 2160 (typical monitor resolution); 4096 x 2160 (official cinema resolution)|
|Ultra HD (UHD)||3840 x 2160|
|QHD aka WQHD aka 1440p||2560 x 1440|
|2K||2560 x 1440 (typical monitor resolution); 2048 x 1080 (official cinema resolution)|
|WUXGA||1920 x 1200|
|Full HD aka FHD aka 1080p||1920 x 1080|
|HD aka 720p||1280 x 720|
This article is part of the Tom's Hardware Glossary.