The content component (com_content) is what you use to write articles. It is extremely flexible and has the largest number of built in views. Articles can be created and edited from the front end, making content the easiest component to use to create your site content.
Joomla! 2.5 continues development of the Joomla Framework and CMS as a powerful and flexible way to bring your vision of the web to reality. With the administrator now fully MVC, the ability to control its look and the management of extensions
Here is another news article.
Here is another news article.
This is a module where you might want to add some more information or an image, a link to your social media presence, or whatever makes sense for your site.
You can edit this module in the module manager. Look for the Side Module.