NTSC is mainly used in USA and Japan. It requires 525 scan lines in each NTSC image, 30 frames per second, and each frame consists of 2 fields constructed in Interlace mode. PAL is a color signal standard first applied in Europe and later used in other areas, including China. PAL requires 625 scan lines in each image, 25 frames per second, and each frame consists of 2 fields constructed in Interlace mode.