You can call a procedure, but when it ends, you always go back to the place where the call was executed from. And sometimes you don't want that — you just want to go to some other section of your code. The jump command does exactly that: it goes straight to a desired section, which should be named and preceded with the label command.
Try this:
program notepad
label start
keyboard 1
jump start
Wow, an infinite loop! To stop it, press Ctrl+F12.