Bitmap graphics are composed of dots, called pixels, arranged in a grid. Your computer screen is a large grid of pixels. In a bitmap version of the leaf, the image is determined by the location and color value of each pixel in the grid. Each dot is assigned a color. When viewed at the correct resolution, the dots fit together like tiles in a mosaic to form the image.

This is a picture of the feature being described.

When you edit a bitmap graphic, you modify pixels rather than lines and curves. These bitmap graphics are resolution-dependent, which means that the data describing the image is fixed to a grid of a particular size. Enlarging a bitmap graphic redistributes the pixels in the grid, often making the edges of the image appear ragged. Displaying a bitmap graphic on an output device with a lower resolution than the image itself can also degrade the image's quality.