In the Installing Applications guide we described how Application Bundles are installed.  We also described how  one can easily drag and drop an icon to the Applications folder to perform an installation.  Many Mac users will tell you that the easiest way to uninstall an Application is to drag it's icon to the Trash.  In some cases, this is true and will suffice.  However, in many cases there's more to meets the eye.  Please read the Application Contents guide for an understanding.

Drag and Drop
Simply drag the application icon to the Trash, then click "Empty Trash" in the Finder menu.  The application will be removed.

Other Files
Some applications will leave files that are not contained in the Application bundle at various locations on the Macintosh HD.  Example include Application Support files and preference files stored under a user's Library folder.  Files can also be stored in the Application Support folder in the system Library folder.

Installers and Uninstallers
If an application was installed with an installer, there's a good chance that an associated uninstaller will be available to perform an uninstall.  Check the application's documentation for details.  In some cases, you may want to re-run the installer to see if an uninstall option is available for applications that have already been installed.

Scripts
Some third party vendors provide uninstall scripts to help you remove an application.  Check with the vendor and their documentation on how to run the script.

Investigate the Application before uninstalling
It's recommended that you do some detective work before you uninstall a program.  You may want to determine if a simple drag and drop will need to be followed up by manual deletes.  The easiest way to investigate an application is to use Spotlight.  Type the name of the application you want to delete and see if folders show up for that application.  If they do find out where they are located on the Macintosh HD.  You may need to manually delete these.

For example, the following folders show up in Spotlight for Real Player:


You may want to perform a search for plist files for the application.  After uninstalling the application, check to see if the items you searched for still exist.  If they don't you may want to manually delete them.  You could also refer to a vendor's documentation on the steps you should take to perform an uninstall.