Mode Ribbon Group

The Mode ribbon group contains the following tools:

Sketch mode
Sketch mode displays the sketch grid, so you can use any of the sketch tools to sketch in 2D.
Section mode
Section mode lets you edit solids and surfaces by working with their edges and vertices in cross-section. You can also use all the sketch tools in Section mode to create and edit solids and surfaces in cross-section.
3D mode
3D mode lets you work directly with objects in 3D space.