What do you call day trading with crypto exchanges?

Im sorry for asking this, and I know that it is probably a very stupid question but I’m new to crypto and my mate was telling me the other day that he likes to exchange a few coins of his ETH into smaller crypto like Solana, then he checks on it throughout the day and when the Solana has gone up a few dollars in value he converts it back into ETH and essentially makes free ETH. I was kinda impressed with this and wanted to know if this is just another variation or way of day trading, or if it’s is called something else.