Are PCs and desktops the same thing?
Yes! A desktop is a computer that is meant to be set up and used in a single location (as opposed to a laptop that you can basically take with you anywhere), and "PC" stands for "personal computer." A personal computer can be either a laptop or a desktop, since you can use either as a personal machine; "PC" also has become a sort of shorthand to help differentiate Windows and ChromeOS machines from macOS desktops.