Question: What is High Definition Television (HDTV)?
High definition (HD) is at the top of the digital television (DTV) spectrum. The reason is simple - resolution. The Advanced Television Systems Committee (ATSC) divided HD into three categories listed in two different forms - 'number of lines + type of scan' or 'number of pixels' (vertical by horizontal).
Here is a breakdown of the HD formats listed by how manufacturers label them on their product summaries:
720p or 720x1280 - 720 lines, progressive scanned
1080i or 1080x1920 - 1,080 lines, interlaced scanned
1080p or 1080x1920 - 1,080 lines, progressive scanned
The number of lines/pixels and type of scan matters because more lines/pixels and faster scan equals a better picture. In ranking the HD signal formats, 720p and 1080i are virtually equal in overall resolution while 1080p is the best.
What Do You Need For HDTV?
How Much Does HDTV Cost?