Yes, Yes, Yes

MacOS and Linux as derivatives of UNIX have a lot of in common. Group of basic tools is a good example, like coreutils in Linux. You indeed have ever used some of them i.e. ls, rm, cat, haven't you?

Well, one of the interesting tools from them is utility yes. It's basically doing one thing: repeatedly print in console char y. You even can specify a second argument, to print something else, like:

yes Bart's yearned a day off

And you will see message Bart's yearned a day off until you kill it. So, you shall try to guess the purpose of utility yes, or just read about it from Wikipedia