What is high-definition television?

High-definition television (HDTV) is a digital television broadcasting system with higher resolution than traditional television systems. The amount of detail shown in a television picture is limited by the number of lines that make it up and by the number of picture elements on each line. The latter is mostly determined by the width of the electron beam. To obtain pictures closer to the quality of 35-millimeter photography, HDTV has more than twice the number of scan lines with a much smaller picture element. American and Japanese HDTVs have 525 scanning lines, and Europe has 625 scanning lines.