What is a plugin?

A WordPress plugin is a separate block of code that adds another function to an already operational blog.

Examples of widely-used plugins are Akismet which filters and blocks spam in comments and WordPress.com Stats which keeps track of blog visitors.

As WordPress is ‘open-source’, plugins can be written by anyone with the required programming skills. Provided that the plugin conforms to the WordPress standard, any programmer can contribute a plugin and make it available for download to the WordPress community.

Find out more about available plugins at http://wordpress.org/extend/plugins.