Passwords usually come with usernames as well. A good username-and-password system will enable you to set up several roles for your computers. Each role will need different types of access, will use different programs and different data.
If an intruder guesses or finds out one person's username and password, they will have access to any programs or data that that person usually has access to. For this reason, you might like to limit what each person is allowed to access.
Most computer systems have something in place which does this. Under most systems, it is called 'permissions'. Your computer manual or local expert can help you set it up on your computers.
Give each person what they need to do their jobs, plus a little personal space of their own. That personal space is often used to 'to-do' lists and other minor things which make their job easier or more comfortable.