(a)   which allows messages to be sent between two users almost instantly, allowing parties to engage in a two-way conversation.

(a)   which identify Web pages that match a query submitted by a user.

(a)   (message boards), which enable users to communicate with each other, although not in real time.

(a)   which allows users to communicate in real time (simultaneously).

(a)   which enables music, video, and other large files to be sent to users in chunks so that when received and played, the file comes through uninterrupted.

(a)   which are small text files that allow a Web site to store information about a user.

(a)   which are online services that support communication within networks of friends, colleagues, and even entire professions.

(a)   which are personal Web pages that typically contain a series of chronological entries (newest to oldest) by the author and links to related Web pages.

(a)   is an XML format that allows users to have digital content, including text, articles, blogs, and podcast audio files, automatically sent to their computers over the Internet.

(a)   are audio presentations—such as a radio show, audio from a movie, or simply personal audio presentations—stored as audio files and posted to the Web.

(a)   are Web applications that allow a user to easily add and edit content on a Web page.

(a)   uses VoIP to transmit audio communication over the Internet.

Web apps, widgets, and gadgets are the examples of (a)