A raster is a grid of pixels or dots that represent images or data in a digital format. Each pixel contains information about color or intensity, allowing for the display of detailed images on screens or in printed form. Rasters are commonly used in various applications, including photography, computer graphics, and geographic information systems (GIS). Rasters differ from vector graphics, which use mathematical equations to represent images. While rasters can capture complex images, they can lose quality when scaled up, leading to pixelation. Common raster file formats include JPEG, PNG, and GIF, each serving different purposes in digital media.