Nothing is better than the best — this is a word for the absolute number one example of something. Best is the opposite of worst.
People love arguing about who's the best at different things. Most people think Michael Jordan is the best basketball player of all-time, and Wayne Gretzky is the best hockey player ever, but there's not much agreement on who's the best football player or baseball player. Best has other meanings too: If you defeated someone, you bested them. People also use this word to recommend something, as in "It would be best to get a lot of sleep."