What is the Practical difference between the Home screen and the Launcher screen? It seems that on my Nexus One, the home screen and launcher screen essentially serve the same purpose: Host application icons, allowing you to launch them.

Are there any other differences, other than the names and the way to reach these screens?

For example, can the launcher screen include widgets?
The main difference is that the launcher screen contains all installed apps on your system. You cannot order it nor do anything but using the icons to access any application.

In the main screen you can:


Add shortcuts to applications (icons
like the ones in the launcher
screen), you can place each icon in
the place you want. 
Add widgets that provide rich
functionalities like clocks,
calendars or weather access.


If you want to compare your phone with a computer, launcher screen is the equivalent of “start menu” in windows, while the main screen(s) are the equivalent to the desktop.