Mnemotechnics are a way to help you remember certain things more easily. It's like using tricks to help remember something. For example, if you wanted to remember the order of the planets, you could use a mnemonic device called 'My Very Educated Mother Just Showed Us Nine Planets' - then if you need to remember the order of the planets, you can just think of the sentence and remember it that way. It's like having a shortcut in your brain for remembering things.