Web Programming & Design 1-5

mobile web browser

A mobile web browser is a web browser designed for mobile devices that can display webpages using HTML, CSS, and JavaScript.

mobile website

A mobile website is a website that is designed for mobile devices with smaller screen sizes and touch interfaces.

Responsive web design / RWD

Responsive web design (RWD) is a collection of techniques to create webpages that adapt to the browser's size.

adaptive website

An adaptive website adapts to the width of the browser at specific widths. Ex: A container is 400 pixels wide when the browser is wider than 500 pixels, but the container shrinks to 200 pixels when the browser is less than 500 pixels wide.

internet

The internet began as four networked computers in 1969. Today, the internet is the largest and most popular computer network, spanning the entire globe.

FTP / File Transfer Protocol

FTP (File Transfer Protocol) was an early way for transferring files over the internet.

World Wide Web / web

In the early 1990s, Tim Berners-Lee was working at a Swiss research institute named CERN and developed a more convenient way for computers to communicate files over the internet. Berners-Lee named his creation the World Wide Web, or simply 'the web'.

webpage / web page

A webpage or web page is a document that is viewed in a web browser.

website

A collection of related webpages are organized into a website.

web server

A web server is a program that serves webpages to web browsers.

HyperText markup language / HTML

HyperText markup language (HTML) is the standard markup language for web documents.

Hypertext

Hypertext is text that has links to other text (and today to images, videos, and more).

markup

Document markup is special markings in the document that provide additional information about links, formatting, and images.

web browser

A web browser is a program that downloads an HTML document from a web server, displays the document to the user with the appropriate formatting, and allows the user to interact with the document, such as clicking hyperlinks to access other documents.

World Wide Web Consortium / W3C

The World Wide Web Consortium (W3C) is the international standards organization that traditionally has controlled a number of web standards, including HTML.

Web Hypertext Application Technology Working Group / WHATWG

The Web Hypertext Application Technology Working Group (WHATWG), an organization that develops a variety of web standards and whose members include the major browser vendors.

HTML Living Standard

WHATWG produces the HTML Living Standard, a continually evolving standard without version numbers that replaces HTML5.

packet

An internet packet contains To and From IP addresses, the information to communicate, and other configuration information.

IP address / Internet Protocol

An IP address (short for Internet Protocol address) is a computer's unique address on the internet (like a house's unique address in the world), usually represented numerically like 198.51.100.7.

IPv4

The original Internet Protocol, known as IPv4, has 32-bit addresses.

IPv6

A new version of the Internet Protocol, IPv6, uses 128-bit addresses, capable of representing 2^128 addresses.

domain name

A domain name is a name for an IP address, such as the name wikipedia.org for the IP address 198.35.26.96; the name is easier to remember and type.

DNS server

When a computer sends a packet using a domain name over the internet, the first step is to contact a DNS server to convert the domain name to an IP address.

DNS

DNS is short for Domain Name System.

root servers

Thirteen main DNS servers (called root servers) exist in the world, and a computer's operating system or an ISP keeps a reference to the root servers' IP addresses.

domain name registrar

Anyone may register an unused domain name with a domain name registrar.

top-level domains / TLD

A domain name belongs to one of numerous top-level domains (TLD), such as .com, .net, .org, .edu, and .gov.

country code top-level domain / ccTLD

Each country is assigned a unique two-letter country code top-level domain (ccTLD) like .uk (United Kingdom), .ru (Russia), and .de (Germany).

second-level domain

Immediately after a top-level domain comes a second-level domain, such as wikipedia in wikipedia.org.

URL / Uniform Resource Locator

A URL (Uniform Resource Locator) is the location of a web resource on the web.

web resource

A web resource is any retrievable item, like an HTML file, image, video, CSS stylesheet, etc.

Scheme

Scheme - Characters at the beginning of a URL followed by a colon ':' or a colon and double slashes '://'.

Hostname

Hostname - The complete domain name following the scheme in a URL.

Path

Path - The characters to the right of the hostname in a URL.

Query string

Query string - Optional characters to the right of the question mark (?) in a URL that provide data for the web server.

Fragment

Fragment - Optional characters at the end of a URL that start with a hash character (#) and refer to a certain location within a webpage.

404

If a web server is reached but the specific requested page isn't found, the server returns a 404 status code, which is a code number for page not found.

Linkrot

Linkrot is the general name for a once valid link that now returns a 404 status code.

HyperText Transfer Protocol (HTTP)

The HyperText Transfer Protocol (HTTP) is a networking protocol that runs over TCP/IP and governs communication between web browsers and web servers.

Transmission Control Protocol/Internet Protocol (TCP/IP)

Transmission Control Protocol/Internet Protocol (TCP/IP) is a protocol suite that governs how data packets are transferred over the internet from one machine to another.

HTTP/1.1

HTTP/1.1 is the HTTP standard used for most of the web's lifetime.

HTTP/2

Many websites are adopting HTTP/2, a relatively new HTTP standard that speeds-up the transfer of information between web browsers and web servers.

HTTP/3

HTTP/3, currently in development, improves the speed of HTTP/2 by using UDP to transport data packets instead of TCP.

DNS lookup

The web browser performs a DNS lookup by sending the domain name to the local DNS and getting back the IP address of the web server hosting the domain name.

HTTP request

An HTTP request is a message sent from the web browser to the web server. Often the request asks the web server to send back a web resource like an HTML file, image, CSS stylesheet, JavaScript file, or video.

HTTP response

An HTTP response is a message sent from the web server back to the web browser in response to an HTTP request. Often the response contains the requested web resource.

start line

The start line specifies the HTTP version being used. A request's start line includes a request type and path; a response's start line includes a status code and phrase.

header field

A header field is a keyword followed by a colon and a value. Header fields supply additional information about the request or response.

message body

A message body contains data being transferred between a web browser and web server. In a request, the message body may be empty or contain submitted form data. In a response, the message body may contain the requested resource.

Internet Assigned Numbers Authority / IANA

The Internet Assigned Numbers Authority (IANA) is a standards organization that manages various internet numbers and symbols, like global IP address allocation, root zone management in DNS, and media types.

request method

An HTTP request method indicates the desired action to perform on a resource.

status code

An HTTP response status code is a three digit number that indicates the status of the requested resource.

browser redirect

A browser redirect is when the web server returns a 301 or 302 status code with a Location header indicating the URL the browser should load next.

URL shortening

URL shortening is a technique to create shorter URLs that redirect to longer URLs.

browser cache

A browser cache is an area on the computer's file system where web content can be stored by the web browser for quick retrieval later.

entity tag (ETag)

An entity tag (ETag) is an identifier for a specific version of a web resource. Ex: 34905a3e285dd11. When the resource changes, so should the ETag associated with the resource.

If-Modified-Since

If-Modified-Since is used with the Last-Modified date/time to request the web server only send the requested resource if the resource has changed since the specified date/time.

Expires

Expires contains a date/time indicating when the requested resource is considered 'stale'.

Cache-Control

Cache-Control is used to specify a number of caching directives.

network sniffer

A network sniffer is software that monitors network traffic and allows users to inspect HTTP requests and responses.

HTTPS

HTTPS encrypts HTTP traffic between a browser and web server so a network sniffer cannot intercept sensitive information in the HTTP traffic like passwords, credit card numbers, financial transactions, etc.

Transport Layer Security / TLS

HTTPS uses a protocol called Transport Layer Security (TLS), which uses asymmetric public keys to encrypt data between the browser and web server.

digital certificate / certificate authority

A website wanting to use HTTPS must acquire a digital certificate, issued by a trusted certificate authority, that contains a public key used by TLS to encrypt data.

mobile device

A mobile device is a handheld computer, like a smartphone or tablet.

Internet of Things

The Internet of Things (abbreviated as IoT) is the global collection of communicating devices that sense and control technology on behalf of humans.

Web accessibility

Web accessibility is the ability of users with disabilities to access and use a webpage with reasonable effort.

Cognitive computing

Cognitive computing is the use of artificial intelligence techniques and access to vast amounts of data to simulate human problem solving in complex situations with ambiguity, changing data, and even conflicting information.

Separation of concerns

Separation of concerns is the design principle of breaking up web content using distinct languages and documents that overlap as little as possible.

HTML

HTML (HyperText Markup Language) is a textual language for creating webpages.

element

An element is a single HTML structure that is represented with HTML tags.

tag

A tag has a descriptive name surrounded by < and > characters that the web browser uses to display content.

link

A link on a webpage is a clickable item that usually causes the web browser to open another webpage when clicked.

Cascading Style Sheets / CSS

Cascading Style Sheets (CSS) is a textual language for describing how a webpage is styled for visual presentation.

CSS rule

A CSS rule specifies styling properties for specific HTML elements.

CSS color

A CSS color can be a pre-defined name like blue, or an rgb value like rgb(50, 100, 255).

rgb

Rgb is short for red, green, blue; all colors can be formed by combining those three colors.

JavaScript

JavaScript is a programming language that runs in a browser, enabling webpages supporting actions like responding to a button click.

variable

A variable stores a value or a reference to a webpage element.

function

A JavaScript function is a named group of statements that can be executed by referring to that name.

/ paragraph

The

element creates a paragraph in an HTML document.

whitespace

A whitespace character is an unprinted character such as the spaces between words and lines of text.

/ line break

The
element creates a line break in a paragraph, such that the content after the line break appears on a new line.

section /

A section is a collection of related content created with a

element.

heading

A heading provides a title for each section.

/

/

/

/

/

Heading elements exist for the first six levels of sections:

,

,

,

,

, and

.

/ emphasized

The element indicates emphasized text, such as text having an emphasized pronunciation when spoken, and is italicized by default.

/ strong importance

The element indicates text that has strong importance, and is bolded by default.

The element denotes a title, such as a book or song title, and is italicized by default.

The element denotes important content that should be semantically highlighted and is rendered with a yellow background by default.

The element indicates text that needs attention, like key words in a document abstract or product names in a review, and renders the text in bold.

The element indicates text in an alternative voice, such as a word or phrase in a foreign language, and is rendered using italics.

The element denotes text that should appear differently from normal text, such as misspelled words, and is underlined by default.

comment

An HTML comment is a portion of the document that is not displayed by the browser.

unordered list /

An unordered list is a collection of items, usually indented and shown using bullets, created with the

element.

list item /

Each list item is created with the

element.

ordered list /

An ordered list is a sequenced collection of items, usually indented and shown using numbers or letters, created with the

element.

type attribute

The

element's numbering scheme is specified with the type attribute.

list-style-type

The CSS property list-style-type provides the ability to change the bullet used in an unordered list and offers more numbering options in an ordered list.

nested list

A nested list is a list within a list item of another list.

A table is an HTML structure created with the element that organizes data into rows and columns.