Apart from the traditional text string password, Windows 8 offers a new form of securing your user account which is by including touch and/or gestures into the procedure. Spoken directly, you are now able to select a picture where you perform three mouse or touch gestures on (circles, line or dots) that will unlock your account if repeated correctly.
To create such a password open the Charms menu by pointing your mouse to the top or bottom right corner and select Settings. Afterwards click on Control Panel. Then navigate to User Accounts and Family Safety > User Accounts > Change Your Windows Password > Make Changes to my account in PC settings > Create a picture password. On the next screen, browse for a picture you want to use as background for the picture password. When you are asked to, perform three gestures on the picture you chose - you can do circles, dots and lines, where circles that are too small will be recognized as dots and any other form will be transformed into one of those three depending on where start and end-points are and how the lines were drawn.
The gestures you have drawn will shortly blink up afterwards, so you now if it is what you actually wanted to draw. After you have drawn three forms, you have to confirm by drawing them again. You can orient yourself on the forms of the picture but should not do so too closely, since it will be really easy to guess afterwards. In the following picture for example, one should not use the bubbles as line reference but look for other forms or links to use - make it easy rememberable for you but hard to guess for others.
If you forget what you drew or the system, for any reason, simply does not accept what you drew (which usually does not happen that easily) - there is still the option to switch back to the regular text string password on log-in screen.