IB Computer Science Option C

IB Computer Science Option C

Selection sort

List searched for next element in order and placed in correct position. Deletes original

Accumulator

Holds the result of operations performed by arithmetic, logical unit

Class

Blueprint for objects that defines properties and methods

Abstraction

Adding structure to object/class so end user only sees interface rather than code

Parity checking

Determines whether bits in a transmission have been corrupted

Head

Contains title, metatags, metadata

Title

Defines title in browser toolbar

IP (Internet protocol)

Network protocol that defines routing to addresses of data packets, all computers have own address that is unique to each device on a network.

Search engine metrics

Used to evaluate and rank web pages

CTR

Click through rate, measures amount of user clicks on a web page after seeing it in search results

Bounce rate

Percentage of users that leave site after only viewing one page

Time on site

Amount of time user spent on site

Page loading speed

Faster loading times preferred

Backlinks

Number+Quality of links leading to page

Mobile responsiveness

How well it can be used mobile

Content quality and relevance

Advanced algorithms to determine these

Freshness

Newer more suspicious

How does DNS work (Domain name service)

Checks own data base to confirm for domain name.

If not present, passed to next DNS in hierarchy.

Continue until name is found or top is reached.

When IP found, sent back to original DNS server.

Server side scripting

Using scripts or programming languages to generate web pages on server side before sending them to clients web browser

Client side scripting

Using scripting/programming languages to add interactive or dynamic behavior to web pages and web applications

TCP protocol meaning

Communication standard that enables programs and computing devices to exchange messages over network

TCP protocol steps

Divides files into packets, sizes defined by IP.

Sends packets off.

Provides error checking.

Established&maintains connection to website in order for file to be downloaded.

White hat SEO techinques

Quality content

Proper use of keywords

Easy navigation

Inbound links

Extensibility

Ability of something to be extended from its initial state. Ability to add custom or user defined elements.

CGI (Common gateway interface)

Part of HTTP. Method for passing data back and forth between server and application. Not dependent on OS.

Decentralized web

Technologies that replace current communication protocols, networks and services and distribute them in a way against censorship

Private computing

Data center where info locked behind paywall, company responsible for maintenance

Public computing

Anyone can access data. Company not responsible for maintenance

Software robot

Software application that runs automated tasks on scripts over internet and can do so at a high rate, usually repetitive tasks

Searching

Queries entered in database and index is searched for matches

Crawling

Exploration of every link/page in web by spiders and returning copy of that page

Indexing

Each web page is analyzed for key words after which page is added to an index

Memory buffer data register

Holds data read from or written to memory

Memory address register

Holds memory addresses of data and instructions

Functions of a web browser

Browser acts as a bridge between URL and DNS

User inputs URL/WEB DN on web bworser address bar

Web browser passes web DN to DNS

Search engine

Software that interrogates a database of web pages

Local client server architecture

Server is central communicator between clients, allows clients to access and manipulate data

Cloud computing

Puts focus on sharing computing resources over internet

Instruction register

Holds instructions being executed by CPU

Program counter

Holds memory of next instruction that is to be executed

Instance

Use of an object within a specific class

Checksum

Method of verifying the integrity of digitally transmitted data

SSL works…

Creates encrypted connection thru shared secret key

User enters HTTPS address

Server shares its SSL certificate, key

Browser verifies certificate

Browser sends encrypted + key

Server decrypts data, receives key

to secure communications over a computer network, ensuring privacy and data integrity.

Ports

Communication endpoints used by network protocols to identify specific processes of services running on devicePHO

PHP

Server side scripting language used to create dynamic webpages. Can be embedded in HTML + executed serverside

mySQL

Database management system used to store and manage data, can create and manipulate it

Javascript

High level programming language used to create interactive effects within web browser

XML

Extensible markup language used for encoding data in a format that is human and machine readable

Semantic web

Structured and linked data w standardized machine readable format. Gtid

Grid computing

Distributed data that involves computing resources across multiple networks to achieve a common goal

Server

Computer that manages access to centralized resource or service in a network

Overloading

Feeding too many arguments into a function/operator in order to see how it handles it

Instantiation class

Creates an object for that classObj

Objects

Basic units of code used to create software applications in OOP

Redundancy

Extra data added to messages for the purpose of error checking

P2P

Peer to peer, machines can interchangeably be the client and server

Surface web

Part of web that can be reached by search engine

Forum

All registered participants can post article/open thread

All can comment w/o moderation

Can still have moderators that can edit or delete posts

Deep web

Part of web that cannot be reached by search engines, protected content

Protocol

Rules that must be followed for a certain successful process to take place

Standard

Set of technical specifications that shouyld be followed to allow for functionality

Hybrid computing

Using both public and private cloud

Authentication

Credentials provided are compared to those in database of authorized user’s info on local computing system

Internet of things

Network of physical objects embedded w electronics and other technology to enable objects to collect and exchange data

Identification

Comparing data samples against all database reference templates in order to establish identity of person trying to access system

SSL

Secure sockets layer, allows for data to be encrypted by allowing a secure exchange of keys, authentication of server and client

Black hat SEO

Unethical ways of increasing a web page’s ranking to gain unfair advantage

Cloaking

Presenting different content or URLS to users and search engines in order to manipulate search rankings

Keyword stuffing

Using excessive amounts of keywords / phrases on a page in order to manipulate search rankings

Hidden text / links

Hiding text or links on page that are only visible to search engines, not users

Link farming

Creating artificial links to website

Ubiquitous computing

Pervasive computing, being able to user computers wherever you are and computing available on all devices

Internet

Network of networks, global network of interconnected computers. Deals w data and packets

Client

Piece of hardware or software that accesses services made by server over network

Network

Group of interconnected computer systems and hardware devices linked together through communication channels to facilitate resource sharing among users

Packet

Basic unit of binary data for communication over digital networks. Routed between origin and destination, contains data traveling over network

URL

Uniform resource locator, every address is typed into web browser, contains protocol, domain name, web page/ Address of resource on internet

HITS Rank

Ranks pages based on combo of its importance as a hub and authority

Web 1.0

Early websites

Static web pages

Presentation of info

HTML, Javascript, CSS

Read only, passive

Local data storage of data and images

Web 2.0

Social media pages, blogs, wikis

Dynamic

User generated content, collaboration

Interactive, social, user driven

Cloud based + distributed images

Text, audio, videos, Javascript

Net neutrality

Equal treatment of providers and users

Creative commons

Way to manage copyrighted material

Allows material to be shared and used friendly manner

Usage limited to purpose and conditions on license

Author of material has all rights

Static web pages

Content can only be changed by admin

Provides same view to all users

Displays exact info stored in HTML file

WWW

Set of software running on internet

White hat SEO

Ethical ways of improving page ranking

Lossy compression

Reduces file size by removing some data from a file

Data cannot be recovered

Loss of quality

Lossless compression

Reduces file size by searching for repeated patterns in data, replacing it with shorter tokens

No data loss

Interoperability

Ability of different computer systems to work cooperatively and share data

Blog

Only owner can post an article/open thread/start discussion

Registered users can comment, owner can moderate

Users cannot edit or delete posts

Open standards

Publicly available standards that are free to user

Aids interoperability

HTTPS

Secure version of HTTP which users SSL encryption standard

Cookies

Small text files stored on user’s computer/mobile device that user visits

Allows website to remember user preference, login info, other unique identifier data

CSS

Cascading style sheets, used to style and format HTML documents

Font, color, layout

Separates presentation from content

Metatags

HTML tags that provide info about a webpage to search engines and other applications that may access the page

Dark web

Subset of deep web

Intentionally hidden from search engines

Requires specialized software like TOR

Assosciated with illicit activity

PageRank

Analyzes links between webpages to rank them in terms of importance

Page more credible if more pages rank to it

Given score 0-1
Quality, quantity, relevance of incoming linksThe algorithm developed by Google to evaluate a webpage's importance based on incoming links and their quality.

Dynamic web page

Allows for user interaction

Allows parts of content to be changed

Can connect to server side databases

Includes server side scripting

Web 3.0

Intelligent web applications

Machine learning, AI

Personalized predictive user experience

Decentralized, distributed

Traditional web

Mostly unstructured

Keyword based searching with with limited accuracy

Data presented as web pages with unstructured text

HTTP

Permits transfer of data exchange over the internet between a client and a server