apcsp vocab

Syntax error

A mistake in typed code that violates the rules of the programming language. Typically, code with syntax errors will not run.

Logic error

A mistake in an algorithm or program that causes it to behave unexpectedly or return the incorrect value.

Run-time error

A mistake in a program that happens only when the program is actually run, such as a program attempting to access memory that does not exist.

Overflow error

Error that results when the number of bits is not enough to represent the number (like a car’s odometer “rolling over”).

Bit

A binary digit, either 0 or 1.

Byte

A sequence of 8 bits.

Roundoff

Error that results when the number of bits is not enough to represent the number with full precision.

Analog data

Values that change smoothly, rather than in discrete intervals, over time.

Lossless

Compressing data in a way that preserves all data away and allows full recovery of the original.

Lossy

Compressing data in a way that discards some data and makes it impossible to recover the original.

Metadata

Data about data, like descriptive information about a file or a row in a database.

Sequencing

The sequential execution of steps in an algorithm or code in a program.

Selection

A Boolean condition to determine which of two paths are taken in an algorithm or program.

Iteration

The repetition of steps in an algorithm or program for a certain amount of times or until a certain condition is met.

Linear search

An algorithm that iterates through each item in a list until it finds the target value.

Binary search

An algorithm that searches a sorted list for a value by repeatedly splitting the list in half.

Reasonable time

A run time for an algorithm that doesn't increase faster than a polynomial function of the input size.

Heuristic

A technique that helps an algorithm find a good solution in a hard problem.

Undecidable

A problem that is so logically difficult, we can’t ever create an algorithm that would be able to answer "yes or "no" for all inputs.

Library

A collection of procedures that are useful in creating programs.

API

Application Programming Interface, a library of procedures and a description of how to call each procedure.

Modularity

The separation of a program into independent modules that are each responsible for one aspect of the program's functionality.

Traversal

The iteration over the items in a list.

Computing device

A physical device that can run a program, such as a computer, smart phone, or smart sensor.

Computer network

A group of interconnected computing devices capable of sending or receiving data.

Bandwidth

The maximum amount of data that can be sent in a fixed period of time over a network connection.

Protocol

An agreed upon set of rules that specify the behavior of a system.

Scalability

The ability of a system to adjust in scale to meet new demands.

IP (Internet Protocol)

The protocol that determines how to address nodes on the network and how to route data from one node to a destination node.

TCP (Transmission Control Protocol)

solve many of the problems that arise from packet-based messaging by having TCP Metada with extra info about order, retransmission instructions, etc to help with all problems that happen to packets

UDP (User Datagram Protocol)

provides a mechanism to detect corrupt data in packets but doesn’t solve other problems with packets so its sometimes called Unreialbe

World Wide Web

A system of linked pages, media, and files, browsable over HTTP.

a massive network of webpages, programs, and files that are accessible via URLs

it is a specific part of the Internet

HTTP (Hypertext Transfer Protocol)

The protocol that powers the Web, used to request webpages from servers and submit form data to servers.

Parallel computing

A computational model which splits a program into multiple tasks, some of which can be executed simultaneously.

Speedup

The improvement in the amount of time a parallelized program takes to solve a problem.

Distributed computing

A computational model which uses multiple devices to run different parts of a program.

Digital divide

The idea that some communities or populations have less access to computing than others.

Crowdsourcing

A model in which many online users combine efforts to help fund projects, generate ideas, or create goods or services.

Citizen science

The participation of volunteers from the public in a scientific research project.

Creative Commons

An alternative to copyright that allows people to declare how they want their artistic creations to be shared.

Open access

A policy that allows people to have access to documents or data for analysis.

PII (Personally identifiable information)

Information about an individual that can be used to uniquely identify them.

Multifactor authentication (MFA)

A method of user authentication which requires the user to present multiple pieces of evidence.

Encryption

The process of scrambling data to

Digital Rights Management (DRM)

tools that restrict where and how a user can use copyrighted media

(ex. Spotify adds a DRM layer to streamed songs so they can’t be listened to anywhere but Spotify)

fair use

allows limited use of copyrighted materials for purposes like criticism, comment, news reporting, teaching, or research

ex. teacher using a passage of a textbook in teaching

no deriatives (creative commons)

work can be distributed/displayed but not modified

share-alike (creative commons(

reused work must have cc license

non-commerical (creative commons)

reused work can only be used for non-commerical purpose

How UDP Works

How TCP Works

establishes a 3 way handshake or make a connection then includes information in the metadata about things so the receiving computer can determine whether packets are out of order, lost, corrupted, etc

Internet

global network of computing devices communicating with each other in some way

words largest computer network

WAN network

bit rate

the number of bits of data that are sent each second

latency (ping rate)

measures how late the bits arrive

time between the sending of a data message and the receiving of that message, measured in milliseconds

IP Address

the unique identifying number assigned to every device connected to the internet

algorithm

step by step process that describes how to solve a problem in a way that always gives a correct answer

polynomial

(n^constant)

ex. n^1, n^5, etc

reasonable run time

superpolynomial

n^k (a variable like 5^k)

unreasonable run time

sequential computing

the computer executes each operation of the program in order, one at a time

neura network

operates similarly to how we think brains work, with input flowing through many layers of "neurons" and eventually leading to an output

they are trained using different ML techniques

Machine Learning (ML)

type of algorithm that automatically improves itself based on experience, not by a programmer writing a better algorithm

database

a system that stores data on a computer in a way that can be easily accessed, updated, queried, and deleted