The RAS (Sun Raster) image format is a raster graphics file format associated with Sun Microsystems. It is used for storing images in a simple uncompressed form, making it suitable for basic graphics applications. RAS files support both monochrome and color images, and they may include a variety of color depths. While less commonly used today, the RAS format was prevalent in Sun workstations and certain Unix environments, where it served as a standard for representing images in the early days of computer graphics.