Question Regarding Errors On Coins.

I noted the mods to move your post to the modern error and variety forum.

Angela, you really should take a moment to google it. I understand you're new to coin collecting, but you seem to have a lot of questions, but then you ignore the answers you're getting. This wikipedia article is a good way to get started understanding the terminology: https://en.wikipedia.org/wiki/Mint-made_errors

It was the first link when I googled "types of coin errors." I'm sure if you do the same search and scroll down, you'll find useful sites too. Good luck.

Oh, by the way, the correct terminology is "doubled die," not "double die." When the hub is pressed into the die, the die slips and creates the image of double. This is what happens now, since the mint uses a one squeeze process to make the dies. In the past, the hubs would be squeezed against the dies multiple times, creating a stronger separation of the doubling. John Wexler's website will help you understand precisely how doubled dies occur.

Here are some threads on what to look for on the different series. If you know what area can be affected, then you will look closer at those areas and spend less time spinning your wheels on what a doubled die doesn't look like:
http://goccf.com/t/265641
A lot of reading and a lot of images. You might want to mark this page to refer back to from time to time. (save the address on a word page)