CMS, Joomla web design,Web design

Yes, you can add or edit the design, the text, the images or any other information on your site at will.

For static sites you need a knowledge of HTML and FTP among other things.

For dynamic sites you dont even need this knowledge. If you can use Notepad or Word you can edit most of the content of your site through easy to use wysiwyg editor. Whats more, you can allot specific rights to people (employees, freelances, professionals) which can allow them to add content to your web site.