The idea is rather simple - just hold the left mouse button and create the pattern which will be used as your password by dragging it along the lines of circles. Set your imagination free! Please remember this pattern, as it will be used as your password and will be stored in the database.
The password can be changed in the "Account Settings" of your profile.
There are two possible options for changing password: either create new pattern, or switch to the ordinary password mode (consisting of letters and numbers). The existing password will be overwritten in the database.