How does the web work? Flashcards
What is the Internet?
: an electronic communications network that connects computer networks and organizational computer facilities around the world —used with the except when being used attributively
doing research on the Internet
What is a Webpage?
A document which can be displayed in a web browser such as Firefox, Google Chrome, Opera, Microsoft Internet Explorer or Edge, or Apple’s Safari. These are also often called just “pages.”
What is a Website?
A collection of web pages which are grouped together and usually connected together in various ways. Often called a “web site” or simply a “site.”
What is a Web Server
A computer that hosts a website on the Internet.
Search Engine
A website that helps you find other web pages, such as Google, Bing, or Yahoo.
A web page can embed a variety of different types of resources such as:
style information — controlling a page’s look-and-feel
scripts — which add interactivity to the page
media — images, sounds, and videos.
Note: Browsers can also display other documents such as PDF files or images, but the term web page specifically refers to HTML documents. Otherwise we only use the term document.
A Website
A website is a collection of linked web pages (plus their associated resources) that share a unique domain name. Each web page of a given website provides explicit links—most of the time in the form of clickable portion of text—that allow the user to move from one page of the website to another.
To access a website,……
type its domain name in your browser address bar, and the browser will display the website’s main web page, or homepage (casually referred as “the home”):
A web server is…….
a computer hosting one or more websites. “Hosting” means that all the web pages and their supporting files are available on that computer. The web server will send any web page from the website it is hosting to any user’s browser, per user request.
Don’t confuse websites and web servers.
For example, if you hear someone say, “My website is not responding”, it actually means that the web server is not responding and therefore the website is not available. More importantly, since a web server can host multiple websites, the term web server is never used to designate a website, as it could cause great confusion. In our previous example, if we said, “My web server is not responding”, it means that no websites on that web server are available.
Search Engine
Search engines are a common source of confusion on the web. A search engine is a special kind of website that helps users find web pages from other websites.
Difference between a Browser and a Search Engine
A browser is a piece of software that retrieves and displays web pages; a search engine is a website that helps people find web pages from other websites.
The History of the internet
It began in the 1960s as a US-army-funded research project, then evolved into a public infrastructure in the 1980s with the support of many public universities and private companies. The various technologies that support the Internet have evolved over time, but the way it works hasn’t changed that much: Internet is a way to connect computers all together and ensure that, whatever happens, they find a way to stay connected.
Ethernet Cable
An Ethernet crossover cable is a crossover cable for Ethernet used to connect computing devices together directly. It is most often used to connect two devices of the same type: e.g. two computers (via their network interface controllers) or two switches to each other. By contrast, patch cables or straight through cables are used to connect devices of different types, such as a computer to a network switch or Ethernet hub.
Router
This router has only one job: like a signaler at a railway station, it makes sure that a message sent from a given computer arrives at the right destination computer.
To send a message to computer B, computer A must send the message to the router, which in turn forwards the message to computer B and makes sure the message is not delivered to computer C.
Modem
This modem turns the information from our network into information manageable by the telephone infrastructure and vice versa.
What does ISP mean?
Internet Service Provider
What is an internet service provider? (ISP)
An ISP is a company that manages some special routers that link all together and can also access other ISPs’ routers. So the message from our network is carried through the network of ISP networks to the destination network. The Internet consists of this whole infrastructure of networks.
What does “IP” stand for as in “IP Adress”
Internet Protocol
What is an IP Adress?
an address made of a series of four numbers separated by dots, for example: 192.168.2.10.
What is an easy way to recognise an IP adress?
To make things easier, we can alias an IP address with a human readable name called a domain name. For example, google.com is the domain name used on top of the IP address 173.194.121.32. So using the domain name is the easiest way for us to reach a computer over the Internet.
Are the internet and the web the same thing?
No.
The Internet is an infrastructure, whereas the Web is a service built on top of the infrastructure. It is worth noting there are several other services built on top of the Internet, such as email and IRC.
What does “Protocols” mean?
How a message is adressed and how it will get passed on.
In the most basic form, what is the internet?
At its most basic, the Internet is a large network of computers which communicate all together.
What is Wifi?
Wireless local network
Wi-Fi or WiFi (/ˈwaɪfaɪ/) is a technology for wireless local area networking with devices based on the IEEE 802.11 standards. Wi-Fi is a trademark of the Wi-Fi Alliance, which restricts the use of the term Wi-Fi Certified to products that successfully complete interoperability certification testing.[1]
What is Bluetooth?
Bluetooth is a wireless technology standard for exchanging data over short distances (using short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485 GHz[3]) from fixed and mobile devices, and building personal area networks (PANs). Invented by telecom vendor Ericsson in 1994,[4] it was originally conceived as a wireless alternative to RS-232 data cables.
Examples of a web browser
Firefox, Google Chrome, Opera, Microsoft Internet Explorer or Edge, Apple’s Safari etc.
Examples of search engines
Google, Bing, Yahoo, Duckduckgo, etc.
Computers connected to the web are called
…clients and servers.
What are clients?
Clients are the typical web user’s internet-connected devices (for example, your computer connected to your Wi-Fi, or your phone connected to your mobile network) and web-accessing software available on those devices (usually a web browser like Firefox or Chrome).
What are servers?
Servers are computers that store webpages, sites, or apps. When a client device wants to access a webpage, a copy of the webpage is downloaded from the server onto the client machine to be displayed in the user’s web browser.
Your internet connection:
Allows you to send and receive data on the web. It’s basically like the street between your house and the places you want to go.
What does TCP stand for?
Transmission Control Protocol
What is TCP/IP mean?
Transmission Control Protocol and Internet Protocol are communication protocols that define how data should travel across the web.
Example: This is like the transport mechanisms that let you place an order, go to the shop, and buy your goods. In our example, this is like a car or a bike (or however else you might get around).
What does DNS stand for?
Domain Name Servers
What is DNS?
The Domain Name System (DNS) is a standard technology for managing the names of Web sites and other Internet domains.
In detail:
Domain Name Servers are like an address book for websites. When you type a web address in your browser, the browser looks at the DNS to find the web site’s real address before it can retrieve the website. The browser needs to find out which server the website lives on, so it can send HTTP messages to the right place. This is like looking up the address of a shop so you can access it.
What does HTTP stand for?
Hypertext Transfer Protocol
What is HTTP?
HTTP: Hypertext Transfer Protocol is an application protocol that defines a language for clients and servers to speak to each other.
What are component files?
Component files: A website is made up of many different files, these files come in two main types: Code files and assets.
What are the two types of component files?
Code files: Websites are built primarily from HTML, CSS, and JavaScript, though you’ll meet other technologies a bit later.
Assets: This is a collective name for all the other stuff that makes up a website, such as images, music, video, Word documents, and PDFs.
What are “Packets?”
Basically, when data is sent across the web, it is sent as thousands of small chunks, so that many different web users can download the same website at the same time.
If web sites were sent as single big chunks, only one user could download one at a time, which obviously would make the web very inefficient and not much fun to use.
Port Numbers
Further, IP Addresses have port numbers that add more detail about how to communicate (think of company phone extensions).
Example:
192.168.0.1
When a port number is needed, the adress is specified as.
192.168.0.1:1234
