Nav is the pattern that defines the navigation pattern.
Nav can be use either for horizontal or vertical navigation structures. This page shows different simple use cases of this pattern that will be applied in a bit more complex patterns such us navbar.
A vertical navigation can be simple or it can be nested, where some of the entries could have interior levels of navigation.
In a nested navigation usually the first level opens the second. Levels that open interior levels must be always identified with a disclosure arrow that indicates this action.
It is possible to nest as many levels as you want in a nested navigation but we encourage to use a maximum of two nested levels.
A nav can be also configured in horizontal for different purposes as can be the navbar.