Standalone WPF Application
WPF applications are installed on end user's machine.
Appear in Start Menu and Add/Remove Programs.
Applications can be installed via MSI or ClickOnce.
User can be offline and use the application. There is no
need for Internet connection.
Newer versions of the application may not be automatically
installed in user's machine.
WPF standalone applications can use WCF for communication.
Applications run in its own window as other windows
applications.
XAML Browser Application(XBAP)
These type of applications are not installed in user's
machine.
They do not appear in the in Start Menu or Add/Remove Programs.
Applications can be automatically deployed via ClickOnce.
Applications are hosted in the browser process.
Can be run only in IE and Firefox.
Newer versions are always installed automatically into the
user's machine.
User must be online to use the application.
XBAP is Windows only. We
can run the application in Windows operating system only.
XBAPs cannot use WCF.
The user machine should have .NET framework 3.0
components.
Silverlight
XBAP is IE and Firefox only. But Silverlight can run in any
browser and platform.
Silverlight is used for creating rich UI web application.
User's machine don't need .NET framework.
Can be embedded in HTML markup and rendered in any browser
using the silverlight plug in.
XABP has 99% features of WPF. But Silverlight is just a
subset of WPF.