How many horizontal lines make up a fast-scan (NTSC) television frame?

In the North American NTSC (fast-scan) analog television standard, a single complete video frame consists of exactly 525 horizontal lines. These lines are drawn rapidly on the screen to create the illusion of a continuous, moving image. Common distractors like 30 and 60 refer to the frame and field rates (frames or fields per second) of the video, not the number of physical lines. The value 1080 refers to modern high-definition digital standards, which did not exist when NTSC analog fast-scan TV was developed.