Pixels are the smallest individual elements that make up digital images. More pixels means higher resolution and quality. Resolution refers to the clarity and quality of an image, which depends on the number of pixels - more pixels means better resolution. Screen resolution specifies the number of pixels that can be displayed horizontally and vertically on a screen, expressed as a ratio such as 1680x1050 pixels. Frame rate is the number of frames displayed per second, typically 25-30 frames/second for movies and video. Different video formats use various codecs, frame rates, sizes and other specifications to encode and store video files.