I see the fallback function of a contract as a way of "depositing" an Ether value to the contract. My question is very simple I guess, but I couldn't find the answer yet.
Is it possible to develop a fallback function to deposit ERC20 tokens into a contract? What's the best way to deposit ERC20 tokens to a contract, VIA contract (by deposit I mean 'ownership transfer')? Like use the key payable but instead of sending ether, send ERC20 tokens.
payablekeyword for tokens, since a Token (ERC20, for example) is a standard which is defined "one layer above the blockchain". Think of it as something like "Ether - hardware layer, Token - software level". Just implement the ERC20 standard functions, and they will allow you to do what you're asking.