I have a few questions about Ethereum and tokens.
1. Do i need to save the private key and json file if i use MEW wallet with Ledger nano s?
2. Tokens that run on Ethereum blockchain , how does that work?
2a. If i send for example Modum, does Modum use the same blockchain as Ethereum or some kind of sidechain?
3. What is really ERC20 tokens?
4. Is gas limit the same as transcation fee is for Bitcoin?
1. You only need one, choose if you want json file or private key to access your etheruem wallet in myetherwallet.
2. Yes all token that is created in ethereum smart contracts uses the same blockchain with ethereum. this is why ethereum experienced delay or scaling problem when this cat game gets trending.
3. Erc20 tokens are assets that are created under ethereums platform. Erc means "ethereum request for comments. This is a protocol for proposing improvements to the Ethereum network. 20 is the unique proposal ID number.
4. Yes it is the same as bitcoin transaction fee.