Very helpful, thank you.
'Its always advisable to post the command (maker) and not to buy from the order book (taker).' I don't quite understand this bit though, please could you explain in even simpler terms? Thanks :-)
let's say you want to buy Ethereum on ETH-BTC market. in case you buy an exising order you are the taker and the fee is more expensive than if you place a buy command (cheaper than the lowest sell order) - in this case you are the maker of the market since you are placing a command