THE INTERNET VAST COMPUTER NETWORK LINKING SMALLER COMPUTER

THE INTERNET – VAST COMPUTER NETWORK LINKING SMALLER COMPUTER NETWORKS WORLDWIDE WHICH UTILIZE SAME COMMUNICATIONS PROTOCOLS. COMMUNICATIONS CHANNEL: TELEPHONE WIRE, FIBER-OPTIC CABLE (e. g. Fi. OS), A HIGH-SPEED MICROWAVE OR SATELLITE DEVICE CONNECTION: CABLE TELEVISION MODEM, DIGITAL SUBSCRIBER LINES (DSL), WIRELESS SATELLITE, DIAL-UP. TYPES OF NETWORK q LOCAL AREA NETWORK (LAN) – SMALL GEOGRAPHIC AREA, SINGLE CHANNEL q WIDE AREA NETWORK (WAN) – CONNECTS LANs, WIDE GEOGRAPHIC AREA § LOCAL, REGIONAL, NATIONAL

THE INTERNET v 1960 s - WORK BEGAN ON THE ARPANET, GRANDFATHER TO THE INTERNET. v. A NETWORK OF GEOGRAPHICALLY SEPARATED COMPUTERS THAT COULD EXCHANGE INFORMATION VIA A NEWLY DEVELOPED PROTOCOL (RULE FOR HOW COMPUTERS INTERACT) CALLED NCP (NETWORK CONTROL PROTOCOL). v. FOUR COMPUTERS WERE THE FIRST CONNECTED IN THE ORIGINAL ARPANET. v. AS THE NETWORK EXPANDED, DIFFERENT MODELS OF COMPUTERS WERE CONNECTED, CREATING COMPATIBILITY PROBLEMS. v. A BETTER SET OF PROTOCOLS CALLED TCP/IP (TRANSMISSION CONTROL PROTOCOL/INTERNET PROTOCOL) DESIGNED IN 1982. v. TO SEND A MESSAGE ON THE NETWORK, A COMPUTER BREAKS ITS DATA INTO IP (INTERNET PROTOCOL) PACKETS, LIKE INDIVIDUALLY ADDRESSED DIGITAL ENVELOPES. TCP (TRANSMISSION CONTROL PROTOCOL) MAKES SURE THE PACKETS ARE DELIVERED FROM CLIENT TO SERVER AND REASSEMBLED IN THE RIGHT ORDER.

THE INTERNET UNDER ARPANET SEVERAL MAJOR INNOVATIONS OCCURRED: EMAIL (OR ELECTRONIC MAIL), THE ABILITY TO SEND SIMPLE MESSAGES TO ANOTHER PERSON ACROSS THE NETWORK (1971); TELNET, A REMOTE CONNECTION SERVICE FOR CONTROLLING A COMPUTER (1972); AND FILE TRANSFER PROTOCOL (FTP), WHICH ALLOWS INFORMATION TO BE SENT FROM ONE COMPUTER TO ANOTHER IN BULK (1973). INTERNET PROTOCOL SOFTWARE WAS SOON BEING PLACED ON EVERY COMPUTER; UNIVERSITIES AND RESEARCH GROUPS BEGAN USING IN-HOUSE NETWORKS KNOWN AS LOCAL AREA NETWORKS OR LANs. THESE IN-HOUSE NETWORKS THEN STARTED USING INTERNET PROTOCOL SOFTWARE SO ONE LAN COULD CONNECT WITH OTHER LANs.

THE INTERNET IN 1986, ONE LAN FORMED A NEW COMPETING NETWORK, CALLED NSFNET (NATIONAL SCIENCE FOUNDATION NETWORK). NSFNET FIRST LINKED TOGETHER THE FIVE NATIONAL SUPERCOMPUTER CENTERS, THEN EVERY MAJOR UNIVERSITY, AND IT STARTED TO REPLACE THE SLOWER ARPANET (WHICH WAS FINALLY SHUTDOWN IN 1990). NSFNET FORMED THE BACKBONE OF THE INTERNET – GREATEST TECHNICAL INNOVATION OF THE 20 TH CENTURY INFORMATION REVOLUTION – LAST HALF OF 20 TH CENTURY

THE INTERNET USING THE INTERNET SOFTWARE TO SEND AND RECEIVE INFORMATION – TCP/IP (TRANSMISSION CONTROL PROTOCOL/INTERNET PROTOCOL SUITE CLIENT/SERVER MODEL OF DATA TRANSFER “HOST” MACHINE DISTRIBUTES INFORMATION, “CLIENT” MACHINE RECEIVES INFORMATION CLOUD COMPUTING – REMOTE MACHINES OWNED BY ANOTHER COMPANY WOULD RUN EVERYTHING FROM E-MAIL TO WORD PROCESSING TO COMPLEX DATA ANALYSIS PROGRAMS

THE INTERNET USING THE INTERNET URL – UNIFORM RESOURCE LOCATOR CONSISTS OF SEVERAL PARTS: § PROTOCOL FOLLOWED BY A COLON & TWO SLASHES § A DOMAIN NAME (A DESTINATION LOCATION) § THE PATH OF THE RESOURCE / SPECIFIC PAGE http: //www. mec. cuny. edu/library/ HTTP – HYPERTEXT TRANSFER PROTOCOL

THE INTERNET USING THE INTERNET INFORMATION ON THE WEB IS CREATED BY THE USE OF HYPERTEXT OR HYPERMEDIA THAT ALLOW TO LINK DIFFERENT PARTS OF FILES. HYPERTEXT DOCUMENTS ARE CREATED BY USING HYPERTEXT MARKUP LANGUAGE (HTML). SPECIAL FORMAT CODES (TAGS) ARE USED TO SET FONTS, INSERT IMAGES, CREATE LINKS.

THE INTERNET SEARCH ENGINES – A UTILITY THAT SEARCHES THE INTERNET, A SITE, A DATABASE. § GENERAL / KEYWORD SEARCH ENGINE (GOOGLE. COM) § META-SEARCH ENGINE (CLUSTY. COM/YIPPY. COM) § SUBJECT SEARCH ENGINE (FINDLAW. COM)