The pages within a module are 'random access': you can jump around them in whatever order you choose.
However, some materials are best approached in a particular sequence. This is done using a 'step-by-step' presentation. This 'exercise' type is not evaluated, that is, you are not required to input answers that are then evaluated.
A 'control bar' allows you to control the display of the steps. You can operate the control bar and move through the steps of the presentation using the mouse or the keyboard.
In this exercise you can select steps using the keyboard. You can see a list of the keys that are available and their functions in the control panel.