Virtual communities exist online in various forms like websites, chat rooms, and newsgroups. They allow people to connect and discuss common interests. Key elements of virtual communities include cellular technology, intelligent software agents, and electronic marketplaces. Early web communities included The WELL, GeoCities, and Tripod. Web portals combine virtual communities, search engines, and directories to provide stickiness and attract advertisers. Examples include AOL, Yahoo, and MSN. Internal web portals can create virtual communities among employees on company intranets.