Before digging into the wonderful world of extensions, it's good to know they come in different shapes and sizes. Basically, there are three types of extensions.
You can manage components through a special Components menu in the backend. They are the most comprehensive extensions, often providing lots of administration options and settings. Component output is usually displayed in the main content area. An example is the Contacts component (to manage a system of contacts, contact details, and contact forms). We'll have a more detailed look at this component later in this chapter.
Modules are blocks that contain special functionality. You've already seen examples at work, such as the menu module. You can manage modules by navigating to Extensions | Module Manager.
Modules usually turn up around the main content area, in the left-hand side and right-hand side column, or in the header and footer. These module...
