ap csp ap exam

computing innovation

* executes a program as a fundamental part of its function
* can be physical, non-physical software, or non-physical concepts

computing system

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

algorithm

* step-by-step procedure that solves a problem/executes a form of computation
* each step must be precise, unambiguous & doable
* can be expressed using only sequence, selection, and repetition

program

* code statements/sequence of instructions that controls a computer
* CPU executes it one instruction at a time
* allows users to gain insight & knowledge about data

application programming interface (API)

* Defines how other programs/web services can use it and communicate with it
* Specifies how procedures in a library behave and can be used
* Useful for real-time data that changes frequently

control structure

programming language statements that control the flow of a computer program

sequence control structure (sequencing)

application of each step of an algorithm in the order the steps are given

selection control structure

uses a Boolean condition to determine which 2 parts of an algorithm are used

repetition control structure

repeating of an algorithm for a specified number of times until a condition is met

input

* -data sent to a computer for processing by a program
* can be tactile, audible, visual, or text

output

* -data sent back by a program to a device
* can be tactile, audible, visual, or text

user interface (UI)

computer application in which a user interacts with a program

function

* -behavior of a program when it is executed
* what the code carries out when running

purpose

* -the problem a program is intending to solve
* the interest the program is pursuing
* the reason why the program is being written

event-driven programming

* -program activated by events like button clicks
* events supply input data to a program, triggering blocks of code in a program that influence its behavior

integrated development environment (IDE)

* -software that provides tools for programming (i.e. UI design, code editing)
* provides a way to interpret and run the program

hardware

* -electronic and mechanical components that execute the instructions of a computer program
* works together with software

software

* -computer programs or code that control the hardware
* serves as interface between an individual and their computer
* works together with hardware

computer

machine that processes information under control of a program

general purpose computer

* -runs on many different platforms (i.e programs, apps)
* includes smartphones and tablets

special purpose computer

* -contains a fixed program, only allowing it to run a single set program
* Includes calculators, watches, a car’s anti-lock braking system

central processing unit

* -hardware that processes the program’s instructions, executing arithmetic and logic operations
* carries out the instructions of a computer program

random access memory

temporarily stores the computer’s programs and data while the power is on

computer chip (integrated circuit/IC)

* -contains millions of electronic circuits
* integrates billions of transistors and logic gates

storage devices

permanently stores data even while the computer is off (i.e. disk drives, flash drives, CDs)

memory

physical device used to store information for use in a computer or other digital electronic device (i.e. disk drive, flash drive)

disk drive

randomly addressable & rewritable storage device

compiler

software that translates human readable code (source code) into binary code

motherboard

houses all of the computer’s main electronic components

input devices

transfers information into the computer’s memory (i.e. touchscreen, mic)

output devices

transfers information out of the memory (i.e. touchscreen, speaker)

network

group of two or more computers linked together

low-level language (machine language)

* -programming language that is machine readable (1’s and 0’s)
* -closer to the machine hardware

high-level language (pseudocode)

* -programming language that is readable by humans, providing the programmer with easy to understand abstractions
* blend of english and code

Moore’s law

number of transistors per sq. in. on ICs will roughly double every 2 years since its invention

data

* distinct information formatted uniquely (i.e. text on paper, bytes stored in electronic memory)
* Provides opportunities for identifying trends, making connections, & addressing problems

metadata

* -Data about data
* -Used for finding, organizing, and managing information
* -Increases the effective use of data or data sets by providing additional information
* -Allows data to be structured and organized

analog data

values that change smoothly, rather than in discrete intervals, over time (i.e. pitch and volume of music, colors of a painting, position of a runner)

big data

* Data sets that are too large to fit on a normal computer/be processed by a standard spreadsheet/database program
* May require parallel systems
* Size of a data set affects the amount of information that can be extracted from it

bit

* -binary digit
* -smallest unit of data
* 1 or 0

parity bit

* -bit that acts on a set of binary values
* added to the leftmost bit of a string of bits to ensure the number of bits are even or odd

byte

group of 8 bits

run-length encoding

* -compression algorithm that represents an image by the length of runs of identical pixels
* lossless compression technique
* used in bitmap (BMP) images

image compression

* -Data compression that reduces the number of bits of transmitted or stored data
* -Size reduction depends on the number of bits/pixels, number of diff. colors in the image, amount of redundancy in the original data representation, and the application of the compression algorithm

lossless compression

* -Data compression technique in which no data is lost i.e. RLE
* Used in BMP images
* Used when the quality/ability to reconstruct the image is important

lossy compression

* -Data compression technique in which some data is lost i.e. JPEG
* Greater size reduction than lossless compression
* Used when minimization of data size/transmission time is important

compilation

* -process of translating an entire source into a single binary file
* more efficient

interpretation

* -process of translating source code into machine language one instruction at a time
* immediately executes each instruction
* easier to debug

abstraction

* -general and simplified representation of something
* formed by the inclusion of details necessary to make the abstraction useful
* reduces complexity, making computer systems easier to use and understand

data abstraction

* -Separates the abstract properties of a data type and the concrete details of its representation
* Manages complexity by giving a collection of data a name without referencing its specific details

procedural abstraction

* -Organizing and encapsulating algorithms in named procedures that can be called by name
* Makes program smaller, easier to read, and allows for code reuse
* Form of refactoring
* Allows programmers to change the internals of the procedure without needing to notify users of the change

refactoring

* -process of restructuring program code without changing its behavior
* simplifies design, making it easier to read & maintain

tag/value pairs

* -stores data
* tag has to be a string
* -value can be a number, string, or list that is stored & retrieved by their tag

variable

* -names a memory location to hold many values in a program
* data abstraction (has associated data storage)
* stores data in the computer's main memory (RAM)
* data is volatile

bug

**-error in computer hardware or software**

simulation

\-Mimics real-world events with the purpose of drawing inferences

\-Involves removing specific details/simplifying functionality.

\-Facilitates the formulation & refinement of hypotheses related to the objects/phenomena under consideration.

\-Computer simulations usually make some simplifying assumptions about the real-world object being modeled.

Internet

* network of networks in which host computers are connected by routers
* governed by the Internet Protocol Suite
* based on open *standards*, enabling it to grow exponentially

protocol

system of rules that govern the behavior of a system

TCP/IP

routes messages between the clients & servers finding a path from the sender to the receiver

HTTP

* system of rules that govern the WWW application
* ensures secure, trusted, encrypted communication over the Internet

World Wide Web (WWW)

* -Internet application that stores a collection of documents, images, and resources based on HyperText Transfer Protocol (HTTP)
* Accessed through a browser

browser

* -program that displays web pages
* used to navigate the WWW

cookies

\-Small files or bits of data that are stored on your computer.

\-Placed when you access a site

data privacy

assures that personal/corporate confidential information is collected, used, protected & destroyed legally & fairly

personally identifiable information

\-information about an individual that identifies, links, relates, is unique to, or describes them.

\-i.e. social security number, age, race, phone number(s)

digital divide

* gap between those who have access to the Internet & computers with those who do not
* usually affected by socioeconomic, geographic, or demographic characteristics

bandwidth

* rate at which data is downloaded/uploaded in a network
* measured in bits per second, kilobits per second, or megabits per second

latency

* measure of the amount of time it takes for a piece of data to reach its destination
* measured in milliseconds

router

transmits data between 2 different networks

cable modem (DSL modem)

connects a home to an Internet Service Provider (ISP)

ethernet

uses wires to connect computers

port

memory location in a server’s RAM that is connected to software that listens for incoming requests

LAN

connects computers within a small area i.e. home/school

wifi (wifi network)

uses radiowaves to connect devices

internetwork

collection of disparate networks that are connected together via routers

redundancy

* The inclusion of extra components that can be used to mitigate the failure of a system if other components fail
* Network redundancy can be accomplished by having more than 1 path between any 2 connected devices

client

computer/software application that requests services from a server located on the internet i.e. web browser

server

host that provides a service i.e. Google’s Gmail service

host

computer that is connected to the Internet i.e. servers

packet

* collection of data used by TCP/IP protocol to transmit data across the Internet
* contains routing data & content of the message

Application Layer

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* Composes a message & passes it to the Transport Layer
* Receives other messages passed on from the Transport Layer

Transport Layer

* Splits a message into packets, adds TCP headers to number the packets, & sends it to the Internet Layer
* Receives packets from the Internet Layer, places them in order, & passes it to the Application Layer when all is received

Internet Layer

* Adds the destination IP address to each packet & passes it to the Link Layer
* Receives packets from the Link Layer & checks to see if it is their IP address
* If it is, it passes it to the Transport Layer
* If not, it sends it back to the Link Layer to pass on to another IP address

Link Layer

* Sends the individual packets to the Link Layers of other IP addresses
* Receives packets from other addresses & passes them to the Internet Layer

IP address

String of numbers separated by periods that identifies each computer using Internet Protocol to communicate over a network

domain name

hierarchical name that identifies a domain & institution on the Internet i.e. .com, .edu, .gov

hostname

domain name that is associated with an IP address

domain name system (DNS)

Internet service that translates domain names into IP addresses

cryptography

* “secret writing”
* art & science of writing secret message

public key cryptography

uses two keys: a public key known to everyone & a private/secret key known only to the recipient of the message.

encryption

process of using a secret key to convert plaintext into ciphertext

symmetric encryption

the same key is used for encryption and decryption

asymmetric encryption

separate but related keys are used for encryption & decryption.

decryption

process of using a secret key to convert ciphertext into plaintext

cipher

system for creating a new alphabet/secret messages

substitution cipher

letters from a ciphertext alphabet are substituted for letters in a plaintext message systematically

Caesar cipher

shifts the alphabet by 3 letters to create cipher alphabet, substituting plain letters with shifted letters

open standard

* -Standards openly available to the public
* Allows devices, services, and applications to work together across a widespread network of networks
* Created and managed through public processes by open international communities
* Key for the exponential growth of the Internet

blacklist

list of email addresses or IP addresses for organizations that are known to be spammers.

whitelist

list of email addresses or IP addresses for organizations that are known to be spam free