Color Components is a meta information mostly found in image files. This includes raw camera files such as NEF or CR2, but also compressed image files like JPG. Even PDF files can contain information about Color Components if an image with such information is embedded in the document.
But what does Color Component say about your image? Any photo or picture stores information about the colors used in the image. This includes the Color Components that make up the color scheme of an image.
The value of the color components is typically either 3 or 1. 3 indicates that there are three Color Components available, e.g. hue, saturation and brightness or R, B and B. 1, however, may indicate that the image is saved in grayscale.