Term | Definition |
computer network | two or more computers connected via communication devices and media |
Internet | a collection of networks that link billions of businesses, government agencies, educational institutions, and individuals |
NPL | British network |
ARPANET | US network |
CYCLADES | French network |
World Wide Web Consortium (W3C) | oversees research and sets standards and guidelines |
Internet 2 (I2) | develops and tests advanced Internet technologies |
Internet Service Provider (ISP) | company that provides access to the Internet to users or subscribers of its service |
Tier 1 | very high capacity WANs operated by very large telecom companies |
Tier 2 | regional WANs operated by large telecom companies |
Local Access ISPs | smaller WANs |
dial-up access | for connecting to the Internet; home or business; computer, modem regular telephone line |
high speed access | for connecting to the Internet; home or business; digital subscriber line |
World Wide Web | an information space of the Internet where electronic documents are identified by URL and interlinked by hyperlinks |
web browser | addition to ISP; software application that allows you to access and view web pages via their URL |
search engine | software program that searches for information on the web |
web crawler | a bot that constantly browses web sites to update an index |
Personal Area Network (PAN) | phone and headset size network |
Local Area Network (LAN) | a single building/campus network |
Metropolitan Area Network (MAN) | a community/city network |
Wide Area Network (WAN) | cities/countries network |
star topology | computers are connected to a central computer; all communications must go through the central computer; basis for most Wifi networks |
bus topology | all computers on the network can communicate with each other; Ethernet networks use this |
hub | small bus with several inputs connecting computers in a small area to the bus network |
repeater | device to connect two bus networks; amplifies signals |
bridge | device to connect two bus networks; any signals intended for a computer on the origin side are returned; only signals mean too r computer on the other side of the bridge are passed through; more efficient than repeater for big networks |
switch | like a bridge but it connects more than 2 bus networks |
router | a computer for connecting incompatible networks |
twisted-pair wire | regular phone lines; simplest and slowest |
coaxial cable | standard cable lines; copper wires surrounded by thick insulation |
fiber optics | fast, accurate, durable; electrons translated into light pulses; insanely expensive |
Client/Server Model | clients make requests; device on network is considered a server and other networks are considered clients; servers satisfy the requests of clients |
Peer to Peer (P2P) Model | devices on network provide service to and receive services from each other |
distributed systems | type of network communication; programs that are executed on different computers |
Cluster Computing | many independent computers work together to provide computating services comparable to a larger coputer |
Grid Computer | members of grid volunteer their computing power to the grid while not in use for themselves |
Cloud Computing | generally owned; huge pools of shared computers can be allocated for use by clients as needed |
redundancy | additional instances of network devices, equipment, and communications mediums are installed within the network infrastructure to ensure the network availability in case a device fails or is unavailable |
latency | amount of time a signal takes to traverse a network |
sensor network | devices distributed throughout a network to monitor environmental conditions like temperature, pressure, sound, etc. |
Network Interface Cards (NICs) | expansion card to connect to Ethernet |
Bluetooth | a type of short range wireless interconnection |
bandwidth | bit-rate of available information capacity |
Internet Protocol (IP) | manages how data travels on the Internet |
IPv4 | current 32 bit IP address format; allows for roughly 4 billion unique addresses |
IPv6 | multi-year transition to 128-bit IP address format happening right now |
routers | devices on Internet to keep packets moving; chooses best path to take at each intersection |
Transmission Control Protocol (TCP) | |
scalable | work with small and large networks |
redundant | have repeated elements |
fault tolerant | because of redundancy, networks won't collapse when part of it breaks down |
web page | electronic document; must follow HTTP protocol |
World Wide Web | collection of web pages |
website | collection of related web pages |
hyperlinks | built-in connections to other documents |
Domain Name System (DNS) | associates text names with device IP addresses |
DNS Servers | connect to Internet setup in a hierarchy to store and look up IP addresses |
DNS spoofing | when a hacker breaks into a DNS server and assigns the wrong IP address to a domain name; sends web page users to an imposter website when they are vulnerable |
registrars | agencies assigned by ICANN |
Top Level Domain (TLD) | suffix ont he end of a domain name |
sub domains | user that registers a domain name can extend that name to obtain identifiers for items that belong to that domain |
Hypertext Markup Language (HTML) | programming language used to created documents to be displayed on the web |
Cascading Style Sheets (CSS) | style definitions used in HTML |
Java Applets | programs embedded into an HTML document |
Java Server Pages (JSP) | small pieces of executable code intertwined with traditional HTML content that are executed by the computer hosting the web page |
information security | the protection of data (information) |
confidentiality | prevents your personal data from being leaked |
data integrity | makes sure only certain people/software have access to change data |
malware | malicious software transferred to/executed on a computer |
virus | inserts itself into existing programs to corrupt data |
worms | autonomous program forwards itself to other computers |
Trojan Horses | enters disguised as harmless program |
spyware/sniffing software | collections info about computer activities and reports back to instigator |
phishing | obtaining into from victim and pretending to be benign |
Denial of Service (DoS) | overloads a computer with messages to distort activity |
spoofing | a computer pretending to be another computer by faking its IP address |
spam | unwanted junk email; not generally malicious |
firewall | network software that blocks dangerous/inappropriate messages from going in or out |
proxy server | limits access; software between client and server shielding client from harmful actions of the server |
antivirus software | software to detect and remove viruses and/or spyware |
spam filter | firewall intended to block unwanted mail; learns to identify spam by users reactions |
passwords | controls access to network but not data once it leaves the network |
encryption | coding and decoding messages so that if they are intercepted they cannot be interpreted |
symmetric encryption | sender and receiver have to have same encryption code |
public key encryption | public and private keys; public= always to send; private = opens |
digital certificates | used by to ensure website downloading is actually a secure website |
CAPTCHA | software to verify that a web form is submitted by a human not a machine |
intellectual property | original work to which one has the rights and for which one may apply for a patent, copyright or trademark |
copyright | the exclusive legal right to print, publish, sell, etc. the expression of an idea and authorize others to do the same |
patent | for inventions |
trademark | for identifiers like company names and logos |
World Intellectual Property Organization | an agency of the United Nations to promote and protect intellectual property |
Digital Millenium Copyright Act (DMCA) | a 1998 US copyright law intended to protect the rights of both the copyright owners and consumers which are usually in conflict |
Creative Commons License | license that enables free distribution of copyrighted work; owner sets up rules for the sharing of and building upon their work |
Open Source Software | license for software that makes the source code available for others to study, change, and distribute for any purpose; encourages a collaborative environment |
Crowd Sourcing | getting input or information from a large number of people, paid or unpaid |
Citizen Science | when professional scientists and people from the general public collaborate on specific studies |
net neutrality | the principle that Internet service providers and governments regulating the Internet should treat all data on the Internet the same, not discriminating or charging differentially |