A contractor has built a Joomla 1.5 extension for us, and I'm confused by an architectural choice he made. I'm not a hardcore Joomla user, so I don't know if the way it was built is normal.

When I install the extension, I get two separate parts:

* A *component* portion that has system-wide settings on it (for example, a setting that turns on and off features for the site as a whole)
* A *plugin* portion that has content-related settings on it (for example, settings that specify which content categories and articles to apply the features to)

I'm not wild about the functionality being split into two sections like this: you have to enable both the component and the plugin to get it to work, and you have to remember which section a particular setting is found on when you want to change it. I prefer the idea of having everything in just one plugin.

Questions for those wiser and more experienced than I:

1. Is it *normal* for an extension to be composed of both a component and a plugin?
2. Is it *technically feasible* to combine any particular functionality into a single component or a single plugin?
3. If the answer to #2 is yes, is it generally *advisable* to combine the functionality?

I hope this question isn't too vague. Thanks for readin' it.