All the facts about the evolution of HDTV

The term high definition was first discovered and used to describe television picture quality standards in the 20th century and HDTV televisions have a long history in the evolution of TV and broadcasting. Originally designed to replace then existing systems that were only able to produce 12 lines of picture resolution, different HD television systems were developed and implemented in different countries.

The US used NTSC using 525 lines of resolution while European countries used a PAL system that was capable of producing 625 interlaced lines instead. This led to having separate broadcasting platforms and format until the late 1990s when DVB (Digital Video Broadcasting) was formally introduced and mandated by regulators around the world. It required wide screen transmission creating the need for bigger televisions and the term HDTV was adopted. Formats used previously before the introduction of DVB are now considered Standard Definition although some countries still recognize those formats as high-definition.

Today most HDTVs are able to produce as average of 720 lines of progressive resolutions and full high-definition (Full HD) is recognized as 1080p or 1080 lines of progressive resolution.

Some computer manufacturers have introduced other versions of high definition including Extreme High definition (1440 lines of progressive resolution) and ultra high-definition Television (4320 lines of progressive resolution) although only extreme high definition is available to most consumers and is optimized for computer based LCD monitors, most notably the Apple iMac 27inch which has 1440p as its native resolution.
For most consumers 720 lines of resolution or 720p HD is satisfactory as it still has the benefits of HD and digital compression as full HD.

Lower prices HDTVs support 720p or HD-ready signals while others come with full HD 1080p support built in. While getting a 1080p HDTV or Full HD TV is the ideal option, most broadcasters are broadcasting using 720p HD so most consumers can still buy an HD-ready HDTV without losing out on the HD experience. For those with a big pocket, there are 3D ready Full HD Televisions available that can support 3D as well as 720p and 1080p resolutions. HDTV has evolved from its early days where 13 lines was considered high definition, to where today almost 100 times that is considered extreme high definition.