Your username, your password. If someone else has used your computer, you’ll have to switch to your username. (when your password doesn’t work, check the username before trying more than a couple of times; otherwise you might lock yourself, or someone else, out)
Logging into another on-site computer: same thing. With the exception of some special software and other minor differences, it doesn’t matter what computer you use.
Logging in anywhere. You still access the same files, the same email, calendar, etc. Your username and password are consistent whenever you log into any computer belonging to the organization. “Computers don’t have passwords, people do.” (don’t take that too literally, but keep the thought) .
When you are done for the day, or leaving a computer for any extended time, please log out (log off, sign out, sign off, or any other similar term). This is good for security, it also lets the machines get updates when you’re not around, and it leaves the computer available if someone else might need it.
Logging out vs. Shutting Down
Generally logging out each day is the right thing to do. If you know that a computer won’t be needed for many days, then shutting down might be more appropriate, but rarely. When machines are on (but logged out), routine maintenance operations can happen during the night without impacting your daily work. This is also a good bandwidth saver, as updates during the day compete with your regular work.