Wow! This turned out to be a little more complex than I anticipated! So I created this little infographic sheet. I hope it helps break down the information in an easily understandable format.
There are many different file types but the most common ones are JPG, GIF, PNG, TIF, PSD, EPS, AI, & PDF. I review each type and how they are typically used. I also explain File Compression: Loss Less vs. Lossy; as well as what the two different types of graphic images are: bitmap vs. vector.
Because there is so much information, although I tried to keep it to a minimum, the page size had to be legal (8.5x14). I am attaching the file for downloading below as well as a websized image.
As usual, if you have any questions, ask away! If I don't know the answer, I hope others who do will pipe in!