Web 3.0 refers to a proposed next stage of the World Wide Web focused on semantics and syndication. It aims to support greater user interaction and collaboration through artificial intelligence and linked data. The key aspects of Web 3.0 include linked data to integrate information from diverse sources, ubiquitous connectivity through various devices, and machine learning to automate tasks and queries. Some examples of potential Web 3.0 applications include personalized recommendations based on user behavior and automated planning of activities like movies and meals. Challenges to developing Web 3.0 include the vastness of online data and ensuring consistency, accuracy and trustworthiness of information.