The Component Mode Menu

The Mode Menu allows switching your selection mode from object selection to different types of component selections like Vertices, Edges, and Faces.

In the default UI layout, this menu is located on the left controller, on the upper side of the touchpad (Vive) or thumb-stick (Oculus).

It will show the icon of the currently active mode, as one of the following icons:

Here is a video explaining the use of the menu:
https://youtu.be/1dggbBZvOic?list=PLYt4XosVlCmWKxhYrVzBwu8yEXVGm3jwg&t=19

Object Mode

text
This mode allows selecting and moving complete objects.

Polygon Face Mode

This mode allows selecting and moving mesh polygons / faces.

Polygon Edge Mode

This mode allows selecting and moving mesh edges.

Vertex Mode

This mode allows selecting and polygon vertices.
When working with curves or NURBS surfaces, this mode allows selecting and editing the control vertices (CVs).