2. Search engine
• A web searchengine is a software system that is designed to search for
information on the World Wide Web. The search results are generally
presented in a line of results often referred to as search engine results
pages (SERPs). The information may be a mix of web pages, images, and
other types of files. Some search engines also mine data available
in databases or open directories. Unlike web directories, which are
maintained only by human editors, search engines also maintain real-
time information by running an algorithm on a web crawler.
4. • A socialnetwork is a social structure made up of a set of social actors
(such as individuals or organizations) and a set of the dyadic ties
between these actors. The social network perspective provides a set of
methods for analyzing the structure of whole social entities as well as
a variety of theories explaining the patterns observed in these
structures.The study of these structures uses social network
analysis to identify local and global patterns, locate influential
entities, and examine network dynamics.
Social network
6. email
• Electronicmail,most commonlyreferred to as emailor e-mailsince ca. 1993,[2] is a
methodof exchanging digital messagesfrom an author to one or more recipients. Modern
emailoperatesacross the Internet or other computer networks.Some early email systems
requiredthat the author and the recipient both beonline at the same time, in common
with instant messaging.Today's emailsystems are basedon astore-and-
forwardmodel.Email serversaccept, forward, deliver, and store messages.Neither
the users nor their computersare required to be online simultaneously; they need
connect only briefly, typically to amail server, for as long as it takesto send or receive
messages.
• Historically, the term electronicmail was used genericallyfor any electronic document
transmission.For example,severalwriters in the early 1970s used the termto
describefax document transmission.[3][4] As a result, it is difficult to find the first
citation for the use of the term with the more specific meaning it has today.
