Yes, those are the options from the login screen. Restart and Shutdown are there just in case you didn't want to get to the Login screen for some reason (booting in recover mode, for example) and don't want to go through the login process just to be able to shutdown or reboot. Guest is an option you can delete in System Preferences/User and Groups, but I find it handy for when someone wants to use your machine to check their own email (visitors, adult children visiting, etc). Guest account can't do much, and when logged off, everything they create as Guest is erased, so it's a nice function to have. However, to get rid of them use System Preferences/User & Groups, click on the lock icon then Login Options and un-check what you don't want to see. To get rid of the Guest User, click on the Guest in the side window and uncheck the "Allow Guests..." options.
I also created an account that has NO login functions or add-ons for troubleshooting. It's totally vanilla. Handy for when something goes awry in my own account and I want to see if it's me or the system in general.