There is a huge variety of widgets that can be added to your blog. A widget is a small piece of interactive web-code that can add functionality to your blog.
To start exploring your widget options, the easiest thing to do is to open the customize window you used on day 1. Choose Widgets from the left-hand menu
Once you start customizing, you can select the area of the site where the widget will be inserted. Not all themes support widgets in all locations, so experiment with placement and widget type.
Widgets are not required add-ons to a site, but some widgets may be useful to keeping you organized or highlighting content you’d like to draw attention to. For example the Tag Cloud widget is a good way to see the most common tags used in your posts in a visual format.