The 3D View is used to interact with the 3D scene for a variety of purposes, such as modeling, animation, texture painting, etc.

Tool Shelf

The Tool Shelf is a context-sensitive region containing tools depending on the current mode (for example, modeling tools in Edit Mode, brush tools in Sculpt Mode…).

For more information on specific tools available, see:

Properties Region

The Properties Region contains properties of the active object and selected objects (such as their locations), as well as properties of the editor itself: