First, a bit of background.
Most pages on your website have one primary piece of content. An example of this primary content would be an "About My Ministry" description or an update describing your latest ministry activity.
In addition to this primary piece of content, your website can also include supplementary content that appears on most or all of your pages. The name and address of your mission agency or supporting church might be an example of this supplementary content.
When you choose a design for your website, that design determines where and how your primary content is displayed. The design also offers one or more extra places that can hold different pieces of supplementary content. Those extra places for supplementary content are called widget areas.
Each kind of supplementary content is available as a widget, and many widgets can be displayed in a widget area offered by the design you choose. See the article "What widgets can I put on my website?" for examples of available widgets.
You can place widgets into the widget areas of your design using the "Widgets" option under the "Appearance" menu of your dashboard.