Knowledgebase

A (usually small) piece of software that adds features to a larger piece of software. Common examples are plug-ins for the CMS(Content Management Systems) like WordPress or Joomla.

The idea behind plug-ins is that a small piece of software is loaded into memory by the larger program, adding a new feature and that users need only install the few plug-ins that they need, out of a much larger pool of possibilities. Plug-ins are usually developed by a third party.