Widgets are independently controlled blocks of content which can be added to 4 zones in your website template. The 4 configurable "Widget Zones" are shown on this page.

Every Page and Module Item in your website can have it's own unique configuration of widgets, you can easily choose which Widgets to include in each Zone, and arrange them in the desired order.

If the Zones aren't used the Main Content area (this content is in the "Main Content" area) will expand into the unused space.