BJC Unit 4 Vocabulary

internet

computer network that uses open protocols to standardize communication

computer network

interconnected computing system that is capable of sending or 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, such as computers, tablets, cell phones, and smart sensors

World Wide Web

system of linked pages, programs, and files that uses the Internet

router

computer that passes information from one network to another

ISPs

(Internet Service Providers) are the companies who sell Internet access to homes and institutions

bandwidth

maximum amount of data that can be sent in a fixed amount of time (for digital data, it is measured in bits per second). Higher bandwidth is better because the data will travel more quickly

cloud

storing data somewhere on the Internet, but you don't know where. The cloud service provider (Google, Dropbox, Amazon, Snap!, etc.) manages the actual storage location

path

sequence of directly connected computing devices that connect a sender to a receiver

routing

process of finding a path from sender to receiver

scalability

ability of the Internet to keep working as it grows

redundancy

inclusion of back-up elements in case one part fails

fault tolerance

ability of a system to work around problems

protocol

set of rules that specify the behavior of a system

IP address

unique number assigned to each device on a computer network

packet

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

packet switching

means that the Internet sends short bursts of information, not long continuous strings

IP

(Internet Protocol) lets your computer pretend it has a direct connection to another computer. The routers at every connection point on the Internet run IP, which transmits packets from one IP address to anothe

TCP

(Transmission Control Protocol) lets your computer pretend it has a reliable connection to the other computer. The computers (including servers) at the two endpoints of a communication run TCP, which guarantees that packets arrive successfully

encryption

process of encoding data to prevent unauthorized access

decryption

process of decoding the data

symmetric encryption

use the same key for both encryption and decryption

public key encryption

uses a pair of keys: a public key for encryption and a private key for decryption. The sender uses the public key to encrypt the message, and receiver uses their private key to decrypt it

SSL/TLS

(secure sockets layer/transport layer security) is the 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

kind of malware that records every key pressed by a user

computer virus

type of malware that spreads and infects other computers. Viruses can attach themselves to legitimate programs

antivirus or anti-malware software

software designed to scan your files and Internet transmissions looking 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

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

DDoS (Distributed Denial of Service) 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

digital divide

unequal access to computers and the Internet based on poverty, racism, sexism, isolation in the countryside, age, and other factors. The digital divide affects both individuals within a country and countries themselves

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

general term for using the Internet to get a lot of people to help solve a problem. (Citizen science is a type of crowdsourcing.)

computing innovation

physical (such as a self-driving car), non-physical software (such as picture editing software), or conceptual (such as the idea of e-commerce), but regardless of the form, they must include a program as an integral part of their function

bit

single unit of data that can only have one of two values. We usually represent the two values as 0 (off) and 1 (on)

byte

eight bitsw

word

sequence of however many bits the CPU processes at a time. As of 2017, words are 32 or 64 bits

binary sequence

string of ones and zeros

analog data

have values that change smoothly, unlike digital data which change in discrete intervals

sampling

measuring values, called samples, of an analog signal at regular intervals

sampling rate

number of samples measured per second

width

the number of bits that a CPU processes at a timew

floating point

uses power of two, instead of 10 like scientific notation, to represent very large or very small values

lossless data compression

are reversible (there is no loss in quality); you can reconstruct the original data (ex. PNG)

lossy data compression

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