Short circuiting is something that will happen when your program is running and it hits a conditional. A short circuit in logic is when you know for sure that an entire complex conditional is either true or false before you evaluate the whole thing.
You honestly do not have to worry a whole lot about short circuiting when coding because this is something that happens when the software is running, not when you are coding. That being said, it is still an important concept to understand when it comes to logic. There is one specific time when this info is very useful.