50Hz systems support three scan rates: 50i, 25p, and 50p, while 60Hz systems support a much wider range of frame rates: 59.94i, 60i, 23.976p, 24p, 29.97p, 30p, 59.94p, and 60p. In the days of standard definition television, case rates were often rounded to whole numbers, for example 23.976p was often referred to as 24p or 59.94i often referred to as 60i. Sixty Hertz HDTV supports both fractional bitrates and slightly different whole bitrates, so strict use of notation is necessary to avoid ambiguity. Nevertheless, 29.97p/59.94i is almost universally referred to as 60i, as well as 23.976p is called 24p. The frame rates PAL, SECAM and NTSC technically only apply to analogue standard definition television, and not to digital or high-definition programmes. However, with the introduction of digital broadcasting and later HDTV broadcasting, countries retained their traditional systems. HDTV in the former PAL and SECAM countries operates at a frame rate of 25/50 Hz, while HDTV in the former NTSC countries operates at 30/60 Hz.  The form factor of hard drives continued to decline as technology evolved. In the mid-1980s, 3.5-inch and 2.5-inch form factors were introduced and became the norm in personal computers. In the early 2000s, it seemed that DVB would be the video standard in the distant future. However, both Brazil and China have introduced alternative standards for high-definition video that exclude the hoped-for interoperability after decades of largely non-interoperable analog television transmission.
3. HD stands for High Density and is a kind of floppy disk. For more information, see our high-density disk definition. If your desire involves a TV or something that includes video, such as a video game console or Blu-ray Disc player, you`ll soon learn new technology terms. High definition? Hard disk? Standard? Sd? 720? 1080? What does all this mean? Current standards for high-definition video in North America were developed as part of the advanced television process initiated in 1987 by the Federal Communications Commission at the request of U.S. broadcasters. In essence, the late 1980s was a fatal blow to most of the high-definition analog technologies that had developed up to that point. Modern HD specifications date back to the early 1980s, when Japanese engineers developed the HighVision 1,125-line interlaced television standard (also known as MUSE), which operated at 60 frames per second.
Sony`s HDVS system was unveiled at an international meeting of television engineers in Algiers in April 1981, and Japan`s NHK presented its analogue high-definition television (HDTV) at a Swiss conference in 1983. HD video can refer to any video system with a higher resolution than standard definition (SD) video. The term high definition once described a series of television systems that appeared in August 1936; However, these systems were only high resolution compared to previous systems based on mechanical systems with only 30 lines of resolution. Continued competition between companies and nations for the creation of a true “HDTV” continued throughout the 20th century, with each new system receiving a higher resolution than the last. In the 2010s, this race continued with 4K, 5K and 8K.2 systems. HD stands for High Definition and describes a standard for video or digital audio. For video, this means 1280 x 720 pixels or 720p on TVs. Further information and links can be found in the definition of HDTV.
Film as a medium has inherent limitations, such as difficulty viewing footage during recording, and suffers from other problems caused by poor film development/processing or poor surveillance systems. Given the increasing use of computer-generated or modified images in films, and the fact that the editing of image sequences is often done digitally, some filmmakers have shot their films in HD format using high-end digital video cameras.