This tutorial will give a brief explanation of a few different image formats.

BMP - This is a high quality format with zero compression. The quality is perfect, however, the size is really unpractical. If you make a wallpaper or something save it as a BMP then zip it. It will now be a reasonable size and can be extracted to retain full quality.

JPEG - This is perhaps the most popular format. If you are working with a picture with many colors you want to save it as a JPEG. When you reduce the quality of the JPEG it blurs the pixels together and causes it to be come unclear. The file size varies directly with the dimensions. In other words, the bigger the picture, the biger the file.

GIF - This is my personal favorite. This is best for small, uncomplicated things. Unlike JPG the dimensions of the graphic do not have a drastic effect on the file size. The file size is mostly influenced by the amount of colors in the picture. If you are only working with two colors, such as black text one white background, you should save it as a gif. GIFs have other attributes such as being animated and transparency.

PNG - Eddie showed this to me. This is like GIF, only the files are a bit smaller. Also this format is safe from whatever the AOL browsers do to fuck up images. The only set back is it isn't an officially accepted format, which means if you go to one on your browser it will try to save it rather than display it.

ART - OK, these are just stupid. Someone sent me these and I had to download a special patch just to view it. If photoshop doesn't support it you know it must be gay. I guess AOL developed this and CS people use them too.

If you find this information inaccurate or have questions post in the forums