High Definition is basically increasing the resolution of digital TV broadcasts to show more detail compared to the 625 lines of PAL or 525 of NTSC. OlderThanTheyThink: Analog broadcasts in HD go back to the 1950s, but did not take off until the 2000s. Furthermore, computer users with VGA monitors have effectively had HD since the 1990s.

These three resolutions are generally regarded as HD:

* 720p (1280x720, progressive-scan)
* 1080i (1920x1080, interlaced)
* 1080p (1920x1080, progressive-scan)

Usually broadcasters tend to choose between 720p and 1080i depending on their type of programming; for instance Creator/{{ABC}}, {{Fox}}, {{ESPN}} and the A&E/Lifetime networks go with 720p to reduce image blur during fast motion in sporting events and films, and to address bandwidth concerns. 1080i broadcasters such as Creator/{{NBC}}, Creator/{{CBS}}, the Discovery networks and Food Network and HGTV go for image clarity. However in many cases the average consumer has no need to understand either format, as they all provide a great picture. 720p sets are cheaper than 1080i televisions, though as prices go down, 720p sets are becoming fewer and fewer. 1080p is mainly a media resolution utilized by camcorders and BluRay as it is not currently possible to broadcast a 1080p signal over the air.

Despite the list below, basically '''everything''' new since 2009 on major networks and cable has been filmed in high definition television in North America. The few shows that haven't, such as ''America's Next Top Model'' and ''BigBrother'', have varying reasons, such as [[AppealToVanity probable unease]] by Tyra Banks over the format, and in the case of ''Big Brother'' the high cost of refitting a show with multiple voyeuristic cameras with the HD variety (which are useless when most of your HardCore fans watch on the web and accept low video quality), or have a budget so low they have to use old SD technology by default. ''ANTM'' finally at least pulled the trigger in March 2012, but most of their setup remains "enhanced definition widescreen", which is marketing code for "not really HD".

The turning point for most programs in {{Syndication}} becoming HD was the 2011-12 season (one show, ''Swift Justice with Jackie Glass'' actually '''[[WhatAnIdiot downgraded]]''' to SD because of the loss of Nancy Grace and a new studio in that season, and was [[IncrediblyLamePun swiftly canceled]]). Generally, the only shows remaining in SD are the trifecta of [=NBCUniversal=]'s trash talk shows (''JerrySpringer'', ''Steve Wilkos'' and ''{{Maury}}'') and others of its ilk, along with most of the low-tier court shows, mainly because ITT Tech and sketchy lawyer ads airing on those shows don't really pay the HD upgrade bill well. Again in 2012-13 however, all of those programs upgraded to "enhanced definition widescreen", good enough to fill the screen at the very least.

The ultimate resolution, which is drooled over by home theater buffs as it's the exact size of a 'frame' of a digital theatrical film, has a width of 4096 pixels and a varying height between 2200-3100 pixels depending on film aspect ratio standard; this is known as "4k" and let's just say right now the cost is in Porsche purchase territory has very little content for it, and you're just better off hoofing off to the theater to experience it.

An increasing number of television programmes are now filmed in the format, though the majority of films are still filmed using celluloid. Movies that were shot on film have also been "high-deffed" from the original prints which technically are already HD (and nearly every film now is transferred to a digital format after editing via computer at a resolution slightly above or roughly twice that of 1080p). With the increasing availability of HD camcorders and the increasing popularity of the winning format in the brief HD-DVD war, [=BluRay=], HD will become the norm. Consumer items such as the iPhone and Flip cams, and even $100 point-and-shoots with HD capability have accelerated this transition even further.

Some classic sitcoms and dramas which are on film can also be remastered into HD if the original negatives are available; this is seen on many shows which air on Universal HD and HD Net, along with programs such as the original ''Series/{{Star Trek|The Original Series}}'', which saw an acclaimed re-release in the format in both syndication and on Blu-ray.

The net result of this has been to show more detail and clarity on pretty much everything, from football replays to craggy faces, and also given both makeup artists and local news anchors who could get by with just a smidge of makeup much bigger challenges to deal with.

It's also resulted in a lot of people buying new televisions, especially in the United States after the FCC had forced the digital conversion (originally planned February 12th, 2009 but delayed by the President to June 12th).

Of the Sixth Generation of game consoles, the PS2 and Xbox both technically supported HD, but very few games used those modes, especially on the PS2, which only had TWO games that supported 1080i (GranTurismo 4 and Tourist Trophy, which, it should be noted, ran on the same GameEngine). [[http://www.hdtvarcade.com/hdtvforum/index.php?s=941aaffdaa06508b4026a82248f98174&app=custompages&do=show&pageId=3 The HDTV Arcade Game Database]] highlights which games do support the 720p and 1080i modes. Homebrew for either platform will be more likely to leverage the higher resolution. Most games (but not all) among all four consoles support 480p, at the very least.

Of the Seventh Generation of video game consoles (the PS3, 360, and Wii), only the Wii doesn't have HD capabilities. This has the side effect of making it so some PS3 and 360 games have near illegible text or HUD elements on non-HD [=TVs=](since the game programmers expected it to be played on widescreen HD sets), a problem not present in the Wii due to the aforementioned lack of HD, though the Wii's 480p resolution is considered enhanced definition. The WiiU, XBoxOne and {{PS4}} - in other words, all current home consoles - are in HD.

For the sake of clarity, the following are what [something] definition is defined as.

* Standard Definition (SD): Depending on the format, it's either 480 or 576 horizontal lines interlaced. The format can be widescreen or not.
* Enhanced Definition (ED): The same as standard definition, but is progressive scan.
* High Definition (HD): 1280x720 progressive scan.
* Full High Definition (FHD): 1920x1080 interlaced or progressive scan.
* WQHD: 2560x1440, usually used on computers and is 4 times the resolution of 720p
* QFHD: 3840x2160, which is 4 times the resolution of 1080p. Used as 4K for displays.
* 4K/8K Ultra High Definition (UHD): 4096x2160 and 7680x4320 respectively.
TheOtherWiki has a much more comprehensive list for your liking. Here are just a few examples.

'''Programmes shot in High Definition:'''
* ''Series/{{Community}}''
* ''Series/DoctorWho'' from "Planet of the Dead" onward
* ''Series/{{House}}'''s Season Six finale was shot on a [[http://en.wikipedia.org/wiki/Canon_EOS_5D_Mark_II DSLR Camera]], though everything previously was shot in 35mm.
* ''Series/{{iCarly}}'' began in 2007 and was broadcast in SD for several years, but was filmed in HD from the pilot. When iTunes introduced support for HD video the show was finally released in HD. Other {{Nickelodeon}} and DisneyChannel shows followed suit, filming & broadcasting in HD.
* ''TheNo1LadiesDetectiveAgency''
* ''Franchise/SuperSentai'' since ''Series/GoGoSentaiBoukenger''
** ''Franchise/PowerRangers'' starting with ''[[Series/PowerRangersSamurai Samurai]]''
* ''Series/{{Survivor}}''
* ''Series/{{Survivors}}''
* ''Series/{{Torchwood}}''
* ''TheOffice''
* ''WheelOfFortune'' since the beginning of the 24th syndicated season and {{Jeopardy}} since the beginning of its 23rd season, both in September 2006. They were the first game shows to be broadcast in HD in the United States.
* ''Series/ThePriceIsRight'' tested the HD format during Season 36's Million Dollar Spectaculars, then made it permanent on the premiere of Season 37 in September 2008.
* ''Series/TheSarahJaneAdventures'' from series 3 onwards

'''Films shot on High Definition Video:'''
* ''Film/TwentyEightWeeksLater''
* ''Film/{{Avatar}}''
* ''Film/TheAvengers''
* ''{{Collateral}}'', save the nightclub shootout scene, which was shot in 35mm.
* ''Film/{{Crank}}'' and its sequel. ''Film/CrankHighVoltage'' used a dozen consumer-grade HD camcorders as [[CameraAbuse crash-cams]].
* ''Film/{{District 9}}''
* ''Film/PublicEnemies''
* ''ComicBook/SinCity'' (Creator/RobertRodriguez has shot all of his movies since ''Film/OnceUponATimeInMexico'' in High-Definition. He's said that with today's HD camera technology, he could have made ''ElMariachi'' for $70, rather than $7,000)
* ''{{Film/Skyfall}}''
* ''Film/SlumdogMillionaire'' - The first film to win the AcademyAward for Best Cinematography to have been shot (mostly) digitally. Some scenes were shot in 35mm and others are 15-fps bursts shot on a DSLR camera.
* ''Franchise/StarWars'': ''Film/AttackOfTheClones'' and ''Film/RevengeOfTheSith'' (Creator/GeorgeLucas is one of the format's biggest proponents). One scene of ''Film/ThePhantomMenace'' also had a scene shot on an HD camera as a test.
* ''Film/SupermanReturns''
* ''Film/TheCuriousCaseOfBenjaminButton''
* ''Film/{{Zodiac}}''