Sierra noticed how distracted the professor seemed to be. Eh. She didn't blame him. She'd rather be outside, too. Preferably on the pitch. Passwords, though. The talk had turned to passwords, and in response, Sierra raised her hand.

"You use them to keep people out of places they're not meant to be, for one. You can also use them to protect someone or something, so that only those who use the correct password can have access," she said.