Gravity has a familiar physical meaning but also a nonphysical meaningâbasically seriousness. Thus, something grave possesses gravity. You can refer to the gravity of a person's manner, though public figures today seem to have a lot less gravity than they used to have. Or you can talk about a grave situation, as in the example sentence.
A wiki is a website where users can add, remove, and edit every page using a web browser. It's so terrifically easy for people to jump in and revise pages that wikis are becoming known as the tool of choice for large, multiple-participant projects.
The World Wide Web (abbreviated WWW or the Web) is an information space where documents and other web resources are identified by Uniform Resource Locators (URLs), interlinked by hypertext links, and can be accessed via the Internet. English scientist Tim Berners-Lee invented the World Wide Web in 1989.