Widgets are made available by many web sites. I have included one on this page in the sidebar. I went to OneBillionBulbs.com and created a group that you can join. The site then gave me a little bit of html code to include in my template for the sidebar. When I insert the code in the template for the sidebar this widget automatically appear there.
The information for this group is updated by the OneBillionBulbs.com website when new members join my group and submit how many light bulbs they have replaced. The updated information then appears automatically in my sidebar. If you join my group, you can see how this works.
Widgets can be many things. You could have a widget in your sidebar from weather.com that provides the weather forecast for a particular zip code. You could include a famous quotations from history widget, a web cam capturing live shots at a particular location in the world, etc.
A word of caution, adding widgets can be fun but can also be overdone. Widgets slow down the time it takes your page to load in a users browser because your blog has to retrieve the information from the other site. If the other site's server is down, this could cause problems with your blog even appearing.
