Raster image editing is based on pixels, which are the components of a raster image. However as Visuals Clipping mentions, there are various ways that colors, textures, brightness and more in a photo can be changed with changing groups of pixels. Another factor is the number of pixels, which determines a certain amount of detail in an image, depending on the size it is displayed or printed. Knowing these elements of resolution and pixel dimensions can then assist users in making decisions about editing images without losing quality unnecessarily in the process of image preparation.