At most jobs today, you’ll find yourself using a computer.  Regardless of whether it’s a laptop or a desktop, it is always a good idea to “lock” your computer when you are going to be away from it for an extended period of time.  What I mean by “lock” is to essentially require a user to enter your password to get to your desktop by placing the login screen on the monitor.  This can be done easily by holding down Ctrl -> Alt, pressing Delete and then selecting “Lock Computer”.  This will make sure that somebody has to login into your computer to be able to use it while you are away.  This is an important security measure as you never know who will be wandering around your office while you are away.