This image format is a lossy format. This means once the image is downloaded it is decompressed into memory and displayed, this format is ideal for most photos, drawings and high colour concentrated images.
This format consists of a grid of tiny pixel squares, this is a lossless format as unlike JPEG nothing is decompressed it contains all the information and colours in the file. GIF images can also contain transparent pixels which make these images ideal as overlay images. With the GIF format there are multiple options for the amount of colours to use in the image with a maximum of 256 colours so this format is not ideal for photos. Another good feature of GIFs is that they can be animated
This format was created to become the new and improved GIF format. The format of PNG is a happy medium between JPEGs and GIFs as you can hold a greater number of colours while still allowing the use of transparent pixels. So why not use PNGs for everything you ask? Well because not all browsers support the PNG format correctly.
Now that you understand the differences in the image formats it is time to get to work.