Standard-definition television in the context of Enhanced-definition television

In mathematics, a ratio (/ˈreɪ.ʃ(i.)oʊ/) shows how many times one number contains another. For example, if there are eight oranges and six lemons in a bowl of fruit, then the ratio of oranges to lemons is eight to six (that is, 8:6, which is equivalent to the ratio 4:3). Similarly, the ratio of lemons to oranges is 6:8 (or 3:4) and the ratio of oranges to the total amount of fruit is 8:14 (or 4:7).

The numbers in a ratio may be quantities of any kind, such as counts of people or objects, or such as measurements of lengths, weights, time, etc. In most contexts, both numbers are restricted to be positive.

High-definition television (HDTV) describes a television or video system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since at least 1933; in more recent times, it refers to the generation following standard-definition television (SDTV). It is the standard video format used in most broadcasts: terrestrial broadcast television, cable television, and satellite television.

Composite video, also known as CVBS (composite video baseband signal or color, video, blanking and sync), is an analog video format that combines image information—such as brightness (luminance), color (chrominance), and synchronization, into a single signal transmitted over one channel. It is most commonly used for standard-definition television, and is sometimes referred to as SD video.

The signal is typically carried on a yellow RCA connector, with separate connectors used for left and right audio channels. In professional equipment, a BNC connector is often used instead. Other connector types may appear in compact consumer devices like digital cameras.

625-line (or CCIR 625/50) is a late 1940s European analog standard-definition television resolution standard. It consists of a 625-line raster, with 576 lines carrying the visible image at 25 interlaced frames per second. It was eventually adopted by countries using 50 Hz utility frequency as regular TV broadcasts resumed after World War II. With the introduction of color television in the 1960s, it became associated with the PAL and SECAM analog color systems.

A similar 525-line system was adopted by countries using 60 Hz utility frequency (like the US). Other systems, like 375-line, 405-line, 441-line, 455-line, and 819-line existed, but became outdated or had limited adoption.

Windows Media Center (WMC) is a discontinued media center application and digital video recorder created by Microsoft. Media Center was first introduced to Windows in 2002 on Windows XP Media Center Edition (MCE). It was included in Home Premium and Ultimate editions of Windows Vista, as well as all editions of Windows 7 except Starter and Home Basic. It was also available on Windows 8 Pro and Windows 8.1 Pro as a paid add-on. It was discontinued as of Windows 10 and the operating system also removes all of Windows Media Center during an upgrade from previous versions of Windows, although it can reportedly be unofficially reinstalled using a series of Command Prompt commands.

Media Center can play slideshows, videos and music from local hard drives, optical drives and network locations. Users can stream television programs and films through selected services such as Netflix. Content can be played back on computer monitors or on television sets through the use of devices called Windows Media Center Extenders. It is also possible to watch and pause live TV. Up to six TV tuners on a tuner card are supported simultaneously. Both standard- and high-definition unencrypted video are supported through DVB-T and ATSC standards. It is possible to view encrypted cable television channels by using an internal or external tuner that supported CableCARD.