The document defines and describes several key digital technologies and online platforms. It explains that email allows people to send and receive electronic letters and share files and information with others. Wikis enable collaborative writing and allow information to be structured by users. Social bookmarking provides a way for users to save, tag, and share bookmarks online. HTML is the code that defines the structure and layout of web pages. Podcasts contain audio and video files that can be downloaded and listened to on various devices. Voice over IP technologies deliver voice and video calls over the internet. Online chat and social networking enable real-time communication, while blogs serve as personal online journals. The world wide web consists of interconnected web pages that can be viewed via the internet.