In addition to the Drafting & Annotation workspace, a few additional preconfigured workspaces are available from the Workspace Switching button. However, for most of this book, I stick with the out-of-the-box Drafting & Annotation workspace (the exception is Part V, which deals with 3D modeling), and I recommend you do the same as you read along.
A workspace is a collection of menus, palettes, toolbars, and/or Ribbon panels tailored for specific tasks, such as 3D modeling or 2D drafting.
After you switch, AutoCAD remembers which workspace you last used and opens in that one. Four standard workspaces are created when you install AutoCAD 2012 (only two come with AutoCAD LT 2012):