Joomla! defines a Component as

Components are Joomla!’s content elements or applications that are usually displayed in the center of the main content area of a template. This depends on the design of the template in use. Components are core elements of Joomla!’s functionality. These core elements include Banners, Contact, News Feeds, Polls and Web Links. Members of the Joomla! community produce third party Joomla! components on a continuous basis. They are freely available to download from http://developer.Joomla.org and a number of other Web sites. 

The entire system is designed to allow extras to be added and bolted in to the system. This can be anything from a shopping system to a forum or chat room.

A Component allows the entire system to be completely changed into a system for something that is more tailored for your market. Like this could be a Real Estate system, or a Car sales System, or even an Model agency allowing you  to add Models through a new admin panel for user friendliness.

But these are just sample ideas, as the World is your oyster, so you can make the rules up. 

We have developers here that can either custom design and make a Component for you or fix one you have that is not working as it should be.

If you need this service, please supply us a full spec of your requirements, and we will get back with a quote.

Also if you need us to install a component, it will take us about 30 Min's, so about £15 labour should be fine for most occasions.

Or if you are having problems and need one fixing, send us the details and we will get back to you with a price and time scale.