AP CSP BJC Unit 4 Vocabulary

Internet

computer network that uses open protocols to standardize communication and involves interconnected but separate computing devices

computer network

interconnected computing system capable of sending and receiving data

computing system

group of computing devices and programs working together for a common purpose

computing device

physical object that can run a program

World Wide Web (www)

system of linked pages, programs, files that can use the Internet

fault tolerance

capability to work around problems (e.g. part of network breaks down)

protocol

type of abstraction; set of rules that specify the behavior of a system; communication standards

redundant network

multiple pathways to create redundancy, allowing for fault tolerance

open protocol

available for use by anyone so that anyone can connect to the network

router

connection between networks that transfers information

internet service provider (ISP)

company that sells internet to homes and institutions

bandwidth

maximum amount of data that can be sent in a fixed amount of time (e.g. bits per second)

cloud

place in Internet to store data; location managed by cloud service provider

routing

process of finding path from sender to receiver

scalability

ability of Internet to keep working as it grows

redundancy

inclusion of backup elements in case one part fails

Internet Protocol (IP) address

unique number assigned to each device on a computer network

Internet Protocol (IP)

direct connections to computers; specifies how a router handles a request for a different IP address

packet

small chunk of data (text, numbers, lists, etc.) and metadata (information about the data) passed through the Internet as a data stream

packet switching

Internet sends short bursts of information, not long continuous strings

Transmission Control Protocol (TCP)

reliable connections to computers; sends packets until they are acknowledged as received

Application Layer Protocols

highest level of abstraction; manage how data is interpreted and displayed; give meaning to bits; e.g. HTTP

Transport Layer Protocols

manage breakdown of message into packets and reconstruction of packets upon arrival; e.g. TCP

Internet Layer Protocols

manage pathways that packets travel; abstraction of Internet as one large network instead of multiple subnetworks; e.g. IP

Network Interface Hardware

manage connection between Internet device and local network; e.g. using WiFi

open standard

anyone can look up a protocol and use it to make new hardware/software without permission

domain name

human-readable way of locating an Internet site

IP address

machine-readable way of locating an Internet site

hierarchy

arrangement with biggest category at the top and subcategories below

domain name system (DNS)

Internet protocol for translating domain names to IP addresses

Internet Engineering Task Force (IETF)

experts in charge of developing and approving protocols for the Internet

encryption

encoding data to prevent unauthorized access

decryption

decoding encrypted data

substitution cipher

substitutes each letter with another letter (symmetric)

symmetric encryption

use the same key for both encryption and decryption

Caesar/shift cipher

shifts the letters in order

public key/asymmetric encryption

uses two keys: public key for encryption, private key for decryption

Secure Sockets Layer, Transport Layer Security (SSL/TLS)

standard used for cryptographically secured information transfer on the Internet

certificate authorities

organizations that issue digital certificates to verify who owns the encryption keys used for secured communications

malware

software that was designed to harm or take partial control over your computer

keylogging software

malware that records every key pressed by a user

computer virus

malware that spreads and infects other computers; can attach to legitimate programs

antivirus/anti-malware software

software designed to scan files and Internet transmissions for malware

firewall

security system that controls the kinds of connections that can be made between a computer or network and the outside world

phishing

security attack in which the victim is tricked into giving up personal information or downloading malware

Denial of Service (DoS) attack

sending a lot of requests to the server at the same time

Distributed Denial of Service (DDoS) attack

uses a virus to flood a server with many requests from many computers at once so that users of that server are denied service

rogue access point

wireless access point that gives access to a secure network without the authorization of the network administrator

secure

transmission cannot be read if it is intercepted

verifiable

transmission is guaranteed to be from who it claims to be from

cryptography

methods for encoding and decoding messages

citizen science

scientific research conducted in whole or part by distributed individuals (many of whom may not be scientists) who contribute relevant data to research using their own computing devices (crowdsourcing)

crowdsourcing

general term for using the Internet to get a lot of people to help solve a problem

computing innovation

must include a program as an integral part of their function; can be physical, non-physical software, or conceptual

bit

single unit of data that can only have one of two values: 0 (off), 1 (on); short for binary digit

transistor

fundamental building block of computer circuitry

byte

group of eight bits

word

sequence of however many bits the CPU processes at a time

binary sequence/bitstream

string of ones and zeros

analog data

values that change smoothly

digital data

values change in discrete intervals

sampling

measuring values (samples) of an analog signal in regular intervals

sampling rate

number of samples measured per second

width

number of bits that a CPU processes at a time

bignum

multiple-word integer

floating point

represents numbers using powers of two (like scientific notation does for ten)

NaN

not a number; result of “illegal” computations

lossless data compression

reversible algorithms; there is no loss in quality; can reconstruct the original data

lossy data compression

algorithms are not fully reversible; can reconstruct only an approximation of the original data

kilo-

10³ units; thousand

mega-

10^6 units; million

giga-

10^9 units; billion

tera-

10^12 units; trillion

peta-

10^15 units; quadrillion

Hypertext Transfer Protocol (HTTP)

ALP; interprets HTML for web formatting

Transmission Control Protocol (TCP)

TLP; simulates reliable, long-term connection by only displaying data once all packets arrive

Simple Mail Transfer Protocol (SMTP)

for sending and receiving emails between servers