Widgets 101 is a document that defines widgets as pieces of web content that can be taken from one place and put somewhere else. It notes that 81% of all web users saw a widget in November 2007, totaling 148 million people. The document suggests three main reasons for widgets' popularity: to express yourself, share content with others, and make your life easier by accessing personalized information from your desktop. It provides several examples of common widgets and concludes by inviting the reader to connect on social media.