Graphics file formats are standardized means of organizing and storing images in a file format.
Image file sizeEdit
For some image formats, the size for storage of an image file is affected by the width and height of the image (image size), the number of possible colors that can be used (color depth) and the number of pixels in the image per section (resolution).
It is just reasonable to compress images since large images tend to eat more storage space. Image compression algorithms are classified into lossy and lossless. Lossy algorithms retain a good quality of the original image, while sacrificing file size. An example of this is PNG. Lossless algorithms compress images well to a small size, but editing, resizing or further compressing the image will reduce the image's quality. An example is JPEG.
Raster and vector graphicsEdit
Raster graphics typically map data from the file to a fixed grid of pixels, where each pixel has its own representation in the file. Zooming in to the image would reveal the individual pixels in the image.
Vector graphics on the other hand uses geometric definitions that are also mapped to a grid. Unlike raster graphics, the lines, points, colors and all the other information are defined geometrically, so zooming in to the image would not reveal individual pixels.
Some images may also be animated. This is usually done by packaging multiple images into one. Supporting formats include SVG, GIF (most common) and APNG.