Display Mode

By default your objects are represented as set in Preferences.

However, right-clicking on the mesh in the Object Browser, and selecting Display Mode, you can display your mesh as:

 

Wireframe,

 

Shading

 

or Nodes.

 

Wireframe can combine with Nodes and Shading.

 

Shading and Wireframe modes can combine with Shrink, however Nodes can't.