Wow this is new to me.. i didn't know there were miners and non-miners. (I thought all nodes were miners). I have a lot more to learn.

So if i understood correctly.. all incoming transactions are in some sort of "common pool". The miners pull these transactions into themselves and validate each transaction independently, add it to their block + solve the crypto puzzle and add it to the Blockchain.

If the miners are extracting information from a shared pool of transactions can the same transaction be in multiple blocks, and therefore be in the Blockchain multiple times?