The Edit Mode toolbar
Use the Edit Mode toolbar to switch between the four ProBuilder Edit modes:

Object mode: the standard Unity mode for selecting and manipulating GameObjects.
Vertex mode: the element mode for selecting and manipulating vertices (points) on a ProBuilder Mesh.
Edge mode: the element mode for selecting and manipulating edges (lines) on a ProBuilder Mesh.
Face mode: the element mode for selecting and manipulating faces (polygons) on a ProBuilder Mesh.
The Vertex, Edge, and Face modes are also known collectively as the Element modes.
Tip: By default, the Edit mode toolbar appears in the top middle of the Scene view, but you can reposition it with the Toolbar Location preference.
Edit mode hotkeys
In addition to the Scene view toolbar, hotkeys (keyboard shortcuts) are also available:
Escapeswitches to Object mode from any other mode.Gtoggles between the Object and Element modes. For example, if you are in Vertex mode, pressGonce to return to Object mode, and press it again to switch back to Vertex mode.Htoggles between the Element modes (Vertex, Edge, and Face).
If you prefer to have dedicated keys for each mode, you can enable the Unique Mode Shortcuts preference.