Internet Vocabulary

1. Protocol: • “a set of rules governing the exchange or transmission of data between devices” (New Oxford American Dictionary) • “it determines type of error checking and data compression used” (http://www.webopedia.com/TERM/P/protocol.html) 2. TCP (Transmission Control Protocol): • “enables two hosts to establish a connection and exchange streams of data” (http://www.webopedia.com/TERM/T/TCP.html) • a connection-oriented protocol with acknowledgment (slide)

3. IP (Internet Protocol): • “a set of rules governing the format of data sent over the Internet or other network” (New Oxford American Dictionary) • “deals only with packets” (http://www.webopedia.com/TERM/T/TCP.html) • “specifies the format of packets and the addressing scheme” (http://www.webopedia.com/TERM/I/IP.html)

4. UDP (User Datagram Protocol): • “a connectionless protocol that, like TCP, runs on top of IP networks” (http://www.webopedia.com/TERM/U/User_Datagram_Protocol.html) • “unlike TCP/IP, UDP provides very few error recovery services, offering instead a direct way to send and receive datagrams over an IP network” (http://www.webopedia.com/TERM/U/User_Datagram_Protocol.html) • a protocol with no acknowledgment (slide)

5. HTTP (Hypertext Transfer Protocol): • “the underlying protocol used by the World Wide Web to define how messages are formatted and transmitted” (http://www.webopedia.com/TERM/H/HTTP.html)

6. DNS (Domain Name System): • “the system by which Internet domain names and addresses are tracked and regulated” (New Oxford American Dictionary) • “an Internet service that translates domain names into IP addresses” (http://www.webopedia.com/TERM/D/DNS.html) • “when a client device connects to any Internet service, a DNS lookup is performed before anything else occurs” (http://searchnetworking.techtarget.com/tip/What-youneed-to-know-about-the-DNS-system) • “provides a really useful layer of abstraction between applications and physical hosts” (http://searchnetworking.techtarget.com/tip/What-you-need-to-know-about-the-DNSsystem)

7. IP address: • “a unique string of numbers separated by periods that identifies each computer using the Internet Protocol to communicate over a network” (New Oxford American Dictionary) • “an identifier for devices on a TCP/IP network” (http://www.webopedia.com/TERM/I/IP_address.html) 8. Packet: • “a piece of a message transmitted over a packet-switching network” (http://www.webopedia.com/TERM/P/packet.html) • a block of data containing ones and zeroes (slide) • contains a header: destination address, source, checksum, and length (slide)

9. Router: • “a device that forwards data packets to the appropriate parts of a computer network” (New Oxford American Dictionary) • “connected to at least two networks and are located at gateways” (http://www.webopedia.com/TERM/R/router.html)

10. Proxy server: • “a server that sits between a client application, such as a Web browser, and a real server that intercepts all requests to the real server” (http://www.webopedia.com/TERM/P/proxy_server.html)

11. Bandwidth: • “the transmission capacity of a computer network or other telecommunication system” (New Oxford American Dictionary) • “the amount of data that can be transmitted in a fixed amount of time or range within a band of frequencies or wavelengths” (http://www.webopedia.com/TERM/B/bandwidth.html) • measured by bitrate, such as megabits/ gigabits per second (https://www.youtube.com/watch?v=ZhEf7e4kopM&index=2&list=PLzdnOPI1iJNf MRZm5DDxco3UdsFegvuB7)

12. Network latency: • “the delay time for a packet to get from one point in the network to another” (http://searchnetworking.techtarget.com/answer/What-is-network-latency) 13. Hop count: • “the number of bridges, gateways, and routers in which the packet travels from one point of the network to another” (https://en.wikipedia.org/wiki/Hop_(networking)) 14. DHCP (Dynamic Host Configuration Protocol): • “assigns dynamic IP addresses to devices on a network, assigning a different IP address every time it connects to the network” (http://www.webopedia.com/TERM/D/DHCP.html) 15. ICANN (Internet Corporation for Assigned Names and Numbers): • “opened applications for new generic top-level domain names (gTLDs) like .London and .Tesco as an alternative to 22 existing gTLDs that include the most common .com and .net” (http://www.computerweekly.com/news/2240113730/ICANN-opensapplications-for-custom-web-domains) • “a nonprofit organization that is responsible for coordinating the maintenance and procedures of several databases related to the namespaces of the Internet - thereby ensuring the network's stable and secure operation” (https://en.wikipedia.org/wiki/ICANN) 16. W3C (Worldwide Web Consortium): • “an international community where Member organizations, a full-time staff, and the public work together to develop Web standards” (https://www.w3.org/Consortium/) • “W3C's mission is to lead the Web to its full potential” (https://www.w3.org/Consortium/) 17. The difference between the Internet and the World Wide Web: The Internet is a massive networking infrastructure that connects millions of computers across the world. The Internet uses a variety of protocols to pass information over the network. While the World Wide Web (WWW) is a way of accessing all of that information using the Internet as the medium. The WWW is built on top of the Internet and uses the HTTP protocol and web browsers. (http://www.webopedia.com/DidYouKnow/Internet/Web_vs_Internet.asp)