I'd like to learn/understand more about L2 Vs L1 transactions.

Recently made a post asking about reducing fees when transferring Eth out of coinbase exchange and got some very interesting and useful answers, which prompted me to start looking at what L2s are. I'm somewhat getting what this is, but not fully. I'd really like if someone could explain. As much detail as you'd like!

Also a question about transferring and storing the eth. First, I tried a small transaction from CB exchange to CB wallet over the polygon network and I now have wrapped ETH. I got an answer for that, but since I would rather own the actual asset ETH, I tried sending some more Eth over the base network instead of Ethereum.

Now this is the part where I probably look really dumb haha, but better to learn now. What exactly happened when I did this? How is it different from sending over the usual network? Perhaps some analogies? The Eth is now in my wallet under a different address.

Also, if I wanted to transfer to ledger, will I need to add an account for ETH on the base network rather than Ethereum network? Or will it automatically show the separate balance of Eth on base.

Update: on CB wallet, the balances of Eth show differently for Ethereum and Base, but the wallet address is the same for both. What does this mean?

And what are the pros and cons of using L2 Vs L1? Other than the lower fees on L2 it seems.