The term plugin is used in MediaPortal to describe almost every feature, since technically all the features are plugins.

All plugins are displayed and configured in Configuration > Plugins, however, features also have their own configuration settings (see below).  

There are several different types of plugins in MediaPortal.

Window Plugins

Window Plugins* *contain a user interface and allow the user to interact with them or alter the user interface.

Feature Plugins

In MediaPortal, features are technically plugins. However features have their own configuration setting, see Configuration.

In Configuration > Plugins, you can only enable/disable the feature or choose to display it on either the Home or Plugins screen.

GUI Plugins

These window plugins enable you to customize the user interface (GUI):

Additional Window Plugins

In addition to the Features and GUI Plugins, some plugins are included with MediaPortal. These plugins are developed and supported along with the MediaPortal software, thus they are only updated when a new version of MediaPortal is released. 

External Player Plugins

External Player plugins play media files using external applications:

Process Plugins

Process plugins work in the background without any user interface:

Extensions - Plugins

The vast majority of plugins are extensions and are provided and supported by 3rd party developers. However, they can be installed using the standard MediaPortal Extension Installer (MPEInstaller or MPEI) and configured using the same interface as all other plugins, see Configuration > Plugins. These plugins are usually Window Plugins, but can be External Player or Process plugins as well.

For more information on extending Mediaportal see Extensions > Plugins.