television

Television is a system for transmitting moving images and sound that can be broadcast over the air, cable, satellite, or the internet for reception by television receivers. A television receiver decodes a video signal and converts it into visible pictures with accompanying audio. Early systems used analog signals; modern television is primarily digital, supporting higher resolution, color, and interactive features.

The development of electronic television began in the early 20th century, with contributors such as Philo Farnsworth and others. The first demonstrations occurred in the 1920s and 1930s, with regular broadcasts beginning in the 1930s and 1940s in some countries. Television became widespread in the postwar period, evolving from black-and-white to color in the 1950s and 1960s. Digital transition and high-definition formats began in the late 20th and early 21st centuries, expanding the range of available content and distribution methods.

Display technology has progressed from cathode-ray tubes to flat-panel formats such as LCD, LED, OLED, and plasma. Popular aspect ratios have shifted from 4:3 to 16:9, with resolutions advancing from standard definition to high definition and beyond (HD, 4K). Broadcast and distribution standards evolved from analog systems (such as NTSC, PAL, SECAM) to digital standards (such as ATSC, DVB, ISDB, DTMB). Television content is delivered through terrestrial, cable, satellite, and internet protocols, with streaming services increasingly prominent.

Programming spans news, dramas, sports, documentaries, and entertainment. Production typically involves networks, studios, and independent producers, funded by advertising, subscriptions, or public funding in various models. The medium has had a broad cultural and economic impact, shaping public discourse, and continually adapting to regulatory, technical, and consumer trends.