CS Principles (Midterm 2)

Semicolon (;)

Used to terminate a statement in javascript

Plus (+)

performs continuation in javascript

<input...>

HTML element to add textboxes, buttons, etc on the webpage

<link ref="stylesheet" type="text/css" href

HTML referring to an external style sheet CSS (mystyle.css)

Static web pages

are characterized by their fixed content, which means that it shows the same content every time the web page is accessed.
Ex: HTML

Dynamic web pages

Web pages that can change on the fly depending on variables, such as the date or time of day.
Ex: Javascript; CSS

Document Object Model (DOM)

Connects web pages to scripts or programming languages by representing the structure of a document; defines the logical structure of documents and the way a document is accessed and manipulated.

With DOM..

Javascript can change/react HTML elements, CSS styles, and add new HTML elements and attributes

Search engine 2 main components

Indexed links and files
Algorithms with query results

Data center infrastructure

All of the physical resources and components that comprise and support a data center; include:
servers
computers
Routers/switching
security
storage
data center management software/applications

Search engines

Apply a search algorithm to the data collected by web crawlers to display relevant information and websites in response to user searches

Web crawlers

Continuous; score documents so that query processors can rank the results; set different set of URLs; download all of the html files for processing of indexers; categorize/review web pages to sed to indexer; wait in intervals so they're not overcrowded

Inverted index

a data structure storing a mapping from content to its locations in a database file or in a document or set of documents

Forward Index

An index into a set of texts. This is usually created as the first step to making an inverted index; list that is not organized into set locations

A web page has a high rank...

If the sum of the ranks of its backlinks are high (more resources to for the algorithm to pull to put on your search results)

Binary patterns

How all data on a compute system is represented (sequences of 1s and 0s)

Parameters

A set of information included to help a process or function operate as intended.

Internet and the Web

The web depends on the internet; internet is independent; if the internet shuts down, web shuts down; if the web shuts down, internet

Protocols

Internet protocol (IP)
Transmission control protocol (TCP)
what the internet is governed by

Packets

To communicate through a network the computer breaks the information down into packets; sent to a router

Recommender system

Lists the things recommended for you (things you're likely to search for); predicts the rating a user might give to an item (algorithm)

Domain name server (DNS)

Translate the names into their corresponding IP addresses

Centralized computer network

Failure of a single machine/connection can islate large portions of the network

Graph

Common data structure that consists of finite sets of nodes and set of edges connecting them

Transmission control protocol (TCP)

Controls the method by which data is broken down into packets and then reassembled when they reach their final destination

Internet Protocol

Concerned for labeling packets for delivery and controlling the packet's paths from sender to recipient

ARPANet

A computer network developed by the Advanced Research Project Agency (now the Defense Advance Research Projects Agency) in the 1960s and 1970s as a means of communication between research laboratories and universities. ARPANET was the precursor to the Internet.

Uniform research locators (URL)

Addresses to locate resources for web pages;
web crawlers/ indexers responsible for different sets of urls; includes:
Protocol (IP, TCP)
Domain (server)
path to resource

Indexers

Used to organize/score documents so that the query processors can use them to rank/filter results; scans all documents downloaded by web crawlers (like storage)

Query Processing

gets information from indexers which was scanned from web crawler to send to the user

World Wide Web (WWW)

a collection of websites or web pages stored in web servers and connected to local computers through the internet; governed by HTTP

World Wide Web (WWW) Structural components

Web Page
Web Server
Web Browser
Search engine
URL
Protocols
domains
path to resource
hyperlinks
HTTPs

Web server

Computers or software applications that stores and delivers web pages upon request

Web browser

Retrieves and displays web pages

Hyperlinks

Clickable connections that link text or images to other pages of the website, out to external websites, or to files posted on a website; connects one web page to another

HTTPS (Hypertext Transfer Protocol Secure)

Used to connect web servers on the internet/local internet

Add java script

<script>...</script>

"Let"

Keyword used to declare a variable locally inside the block in javascript

"Const"

Keyword used to declare constant variable that can't be changed once assigned a value in javascript

Event

The result of a web page once it loads

Functions

Can be defined in the <head> or <body> section of a document

If else statements

If you need to make a choice between more than two alternatives

Octal number system

a base-8 system, consisting of the symbols 0 through 7; reduces errors in reading binary; common in early computing

Unix file permission

Octal code represending permission for three groups:
Owner
Group
Others
Different binary permissions:
Read (=4);Write (=2);Execute (=1); no permissions (=0)

Binary to Octal

1. Group code into 3 digits
2. Right to left
3. each 3 numbers represent octal digit value
(find in chart)

Decimal to Octal

1. Divide by 8
2. Keep track of remainder
3. Continue dividing by 8 without remainder until there are no remainders left of each product
4. Put together all remainders

ASCII

a code for representing English characters as numbers, with each letter assigned a number from 0 to 127

ISO-8859-1

An extended version of the ASCII character set., each letter assigned from 0 to 256; suitable for some languages in wester world

UTF-8

A coding system for storing characters in bits, extending the 8-bit ASCII coding system to include international characters by sometimes using more than 8 bits.

Internet

Moves computerized information (data) from one place to another; governed by IP

Distribution networks

real, tangible systems of interconnected sources and destinations through which products pass on their way to the final customers

Packet switching

the transmission technology that divides blocks of text into packets; flow in many routes determined by the fasted and most efficient

Routers

Computers that receive packets and pass the packets on toward their destination

Internet back bone

a collection of high-speed data lines that connect major computer systems located around the world; highway that connect cities
High speed cable
high-capacity Nodes

Search engine components

Infrastructure
crawling algorithms
indexing algorithms
query processing/ranking

Infrastructure

Geographically distributed data centers; clusters of computers

Clusters functions

Crawling
indexing
query processing

Social network

Relationship between 3 or more entities communicating and sharing information

Cookies

computer program, installed on hard drives, that provides identifying information; saves browsing information

social network analysis (SNP)

a method for examining relationships in a community, often conducted by identifying who people turn to in times of need