On January 27, 1926, John Logie Baird, a Scottish inventor, gives the first public demonstration of a true television system in London, launching a revolution in communication and entertainment. Baird's invention, a pictorial-transmission machine he called a "televisor," used mechanical rotating disks to scan moving images into electronic impulses. This information was then transmitted by cable to a screen where it showed up as a low-resolution pattern of light and dark. Baird's first television program showed the heads of two ventriloquist dummies, which he operated in front of the camera apparatus out of view of the audience.

Baird based his television on the work of Paul Nipkow, a German scientist who patented his ideas for a complete television system in 1884. Nipkow likewise used a rotating disk with holes in it to scan images, but he never achieved more than the crudest of shadowy pictures. Various inventors worked to develop this idea, and Baird was the first to achieve easily discernible images. In 1928, Baird made the first overseas broadcast from London to New York over phone lines and in the same year demonstrated the first color television.

The first home television receiver was demonstrated in Schenectady, New York, in January 1928, and by May a station began occasional broadcasts to the handful of homes in the area that were given the General Electric-built machines. In 1932, the Radio Corporation of America demonstrated an all-electronic television using a cathode-ray tube in the receiver and the "iconoscope" camera tube developed by Russian-born physicist Vladimir Zworykin. These two inventions greatly improved picture quality.

The British Broadcasting Corporation (BBC) inaugurated regular high-definition public broadcasts in London in 1936. In delivering the broadcasts, Baird's television system was in competition with one promoted by Marconi Electric and Musical Industries. Marconi's television, which produced a 405-line picture--compared with Baird's 240 lines--was clearly better, and in early 1937 the BBC adopted the Marconi system exclusively. Regular television broadcasts began in the United States in 1939, and permanent color broadcasts began in 1954.