I've been trying to understand what is a smart contract. According to the GitHub post, the ELI5 version is that you're basically paying a bunch of computers on a network to process a piece of code that you send to it. I think you can think of it similar to Amazon's AWS but runs on more basic code. The costs to run a smart contract varies with the price of gas, which is paid in ETH.

I'm not sure why I didn't find this before, but the main Ethereum website is very well written for a newbie. I plan to spend the afternoon reading up on some basic topics.

I had this question in my mind today and did some research on this topic.

ERC20

Ethereum is very versatile and allows other types of altcoin to be built on top of it (e.g., BAT). ERC20 is this standard. Anything that is fungible and built on Ethereum is using ERC20. If you would like to see what other coins use the ERC20 standard, you can go to the Trezor website. There are literally hundreds of them. You can also view ERC20 coins in your wallets.

ERC721

Anything that is non-fungible (e.g., one of a kind type stuff), is built using the ERC721 standard. These are starting to get very popular. The most common ones are NBA Topshot and Beeple's artwork that sold for $69 million. So far, I'm not aware of any wallet that supports ERC721 so you cannot view your ownership that way.

Let me know if you have any questions or follow-ups. I find this topic very fascinating. If someone knows how ERC20 rewards ETH holders, please share. I don't think someone who trades BAT is actually paying a ETH fee when transacting but I may be wrong.

I've seen many stores proudly display "We accept Bitcoin here" stickers but I haven't seen the same for Ethereum. Why is that? 

I am trying to understand how Ethereum manages accounts and addresses. Unlike Bitcoin which you can generate an unlimited number of addresses, it seems you can only create one Ethereum address if you wish to spend it in one transaction. 

My understanding is that with Bitcoin you can send bitcoin from multiple addresses as long as it is coming from one account. Ethereum, on the hand, seems to only have one account, one address. To make matters more confusing, you can have ERC-20 tokens (e.g., BAT) transact using an ETH address. Before I transferred BAT from Gemini to my Trezor wallet, I was perturbed because it seemed illogical -- how can one type of coin get transferred to a different address? I had read stories of people losing their bitcoins forever due to carelessness in mixing up other cryptocurrency addresses (e.g., sending BTC to an ETH address) and I was determined not to make that mistake. When my BAT transaction using an ETH address went through, I was elated! This is such an interesting discovery for me but for someone who is 100% brand new to crypto, this can seem very confusing and off-putting. 

I am going to learn more about how Ethereum and ERC-20 handles transactions in the coming weeks.

Edit: Based on this Reddit thread, it's normal for Ethereum to have only one address per wallet.