Versor provides, and makes easily accessible, cursor movements in a variety of groups of “dimensions”, such as:
|functions||depth of brackets||expressions||chars
Some of these operations are already present in GNUemacs (but not all of them easily reachable; some require complex chording, and some may even need to be accessed through M-x), and some are added by Versor. Versor puts them all in easy reach on the arrow keys.
Although GNUemacs uses its modes to put the most useful commands for each mode directly on single keys, there are more dimensions mentioned above than will fit at the same time on the few arrow keys available (just two dimensions). However, note that the available dimensions are conveniently listed in a two-dimensional table, as above.
Conveniently, the arrow keys provide two dimensions, just like the two dimensions of the table above. Versor uses the arrow keys themselves, with a modifier key, to select a pair of adjacent dimensions from one of the rows above, and assign them to the arrow keys.
You will notice (unless your display cannot render this) that a unit of text, of the same size as the dimension you are using, will be highlighted, after each Versor command. This is called the selection; it is what Versor regards as the cursor. The normal GNUemacs cursor appears at the start of it (or occasionally at the end), and all normal GNUemacs operations are available and will use the normal cursor. In GNUemacs versions from 21 onwards, the colour of the selection highlighting changes to indicate the current dimension; there is also an indication in the mode line.
The Versor selection highlight disappears at the start of every command (and is restored at the end of each Versor command), so when you use GNUemacs commands other than Versor commands, Versor quietly becomes invisible, until you use one of its commands again.