20. H.323 Last modified: Wednesday, May 03, 2006 An International Telecommunications Union (ITU) standard that provides specification for computers, equipment, and services for multimedia communication over packet based networks that defines how real-time audio, video and data information is transmitted. H.323 is commonly used in VoIP, Internet Telephony, and IP-based videoconferencing. Users can connect with other users over the Internet and use varying products that support H.323. This standard is based on the Internet Engineering Task Force (IETF) Real-Time Protocol (RTP) and Real-Time Control Protocol (RTCP), with additional protocols for call signaling, and data and audiovisual communications. (~webopedia)
21. Web conferencing is used to conduct live meetings or presentations via the Internet. In a web conference, each participant sits at his or her own computer and is connected to other participants via the internet. This can be either a downloaded application on each of the attendees computers or a web-based application where the attendees will simply enter a URL (website address) to enter the conference. (~wikipedia)