The Key to being a good dungeon master is improvisation. You need to be able to improvise a conversation on the fly, improvise different voices and personalities for each and every NPC in the game, but most importantly, you need to be able to improvise a story around the group of murder-hobos that are running around your maze, like headless chickens, activating every possible trap you set and even finding new ways to get themselves into parallels situations.
The Key to being a good player, on the other hand, is to figure out the dm's plans, ask as Many annoying questions as you can, touch absolutely everything you see, be rude to any NPC you meet along your adventure, steal whatever isn't bolted down and in general - make your dm's life as hard as possible.
At least that's what we understand from all these dnd memes we gathered for you today.