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.
A webpage is a document that is designed to be displayed in a web browser. A webpage usually contains text and images formatted in HTML. Occasionally, other types of content are also embedded in webpages, such as Flash videos and music files. Webpages are so called because they are said to reside on the World Wide Web.