Early in the history WordPress development added support for Widget areas. Typically that meant the sidebar. Instead of hard coding the content of the sidebar it would be made “widget ready”. Anyone could quickly add and arrange the content of the sidebar. Adding, moving, removing content became easy. A few clicks of a mouse and major content changed can be made to sidebar navigation.
Widget Area Evolution
It didn’t take long before theme developers realized they could add widget areas to any area of a theme. Soon widget support was added to headers, footer, and content areas of a theme. But not all themes provide this kind of support. The ones that do define those widget areas and size. Flexible to a point, but you have to make sure your content fits in those areas.
Custom Widget Area Support
You don’t want generic? You want to have your site to be built for YOU. Well, with a little code addition and some tweaking of the theme additional widget areas can be added to almost any WordPress theme. (Some themes, don’t want it to be easy, Thesis comes to mind) But for the most part adding a widget area so you can add and change content when you want to make a change is possible.