Transcript The History of the Internet

The Internet
The Beginning of the Internet
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The Internet started when the Advanced
Research Projects Agency (ARPA) of the
United States Defense Department began a
network called ARPANET in 1969.
It was used as a tool to link university and
government research centers via a
nationwide network that would allow a wide
variety of computers to exchange information
and share resources.
Father of the World Wide Web
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In 1990, Tim Berners-Lee produced the first
version of the World Wide web, the first web
browser and the first web server.
In 1991 it was put online
The first web page address was
http://info.cern.ch/hypertext/WWW/TheProjec
t.html
WC3
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In 1994, Berners-Lee founded W3C (World
Wide Web consortium) at the Laboratory of
Computer Science (LCS) at the
Massachusetts Institute of Technology in
Boston. This is an organization to try to
improve the quality and standard of the world
wide web.
Internet definition
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The Internet is not owned or controlled by any
company, corporation, or nation.
It connects people instantaneously through
computers, fiber optics, satellites, and phone lines.
According to Internet Live Stats, as of December 30,
2014 there was an estimated 3,037,608,300 Internet
users worldwide.
The number of Internet users represents nearly 40
percent of the world's population.
The largest number of Internet users by country is
China, followed by the United States and India.
Networks
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The Internet is the largest computer network in the world,
connecting millions of computers. A network is a group of two or
more computer systems linked together.
There are two main types of computer networks:
1. Local Area Network (LAN): A LAN is two or more connected
computers sharing certain resources in a relatively small
geographic location, often in the same building. Examples
include home networks and office networks.
2. Wide Area Network (WAN): A WAN typically consists of two
or more LANs. The computers are farther apart and are linked by
telephone lines, dedicated telephone lines, or radio waves.
The Internet is the largest Wide Area Network (WAN) in
existence.
Servers
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You may have heard someone say
something like "The server is down" or "We're
having problems with the e-mail server."
A server is a computer that "serves" many
different computers in a network by running
specialized software and storing
information. For example, webpages are
stored on servers.
The Cloud
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You may have heard people using terms like the
cloud, cloud computing, or cloud storage. But
what exactly is the cloud? Basically, the cloud is the
Internet—more specifically, it's all of the things you
can access remotely over the Internet. When
something is in the cloud, it means it is stored on
servers on the Internet instead of on your computer.
It lets you access your calendar, email, files,
and more from any computer that has an Internet
connection.
https://www.youtube.com/v/gu4FYSFeWqg?version
=3&autoplay=1&fs=1&hl=en_US&rel=0
Packets
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Most data moves over the Internet through packet switching. Suppose
you send an email to someone in China. Instead of opening up a long
and convoluted circuit between your home and China and sending your
email down it all in one go, the email is broken up into tiny pieces
called packets. Each one is tagged with its ultimate destination and
allowed to travel separately. In theory, all the packets could travel by
totally different routes. When they reach their ultimate destination, they
are reassembled to make an email again.
Packet switching is efficient because you don't have to have a
permanent connection between the two places that are communicating,
so you're not blocking an entire chunk of the network each time you
send a message. Many people can use the network at the same time
and since the packets can flow by many different routes, depending on
which ones are quietest or busiest, the whole network is used more
evenly—which makes for quicker and more efficient communication all
round.
Packets Example
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what if you dismantled your home, numbered all the bricks, put each
one in an envelope, and mailed them separately to Africa? All those
bricks could travel by separate routes. Some might go by ship; some
might go by air. Some might travel quickly; others slowly. But you don't
actually care. All that matters to you is that the bricks arrive at the other
end, one way or another. Then you can simply put them back together
again to recreate your house. Mailing the bricks wouldn't stop other
people mailing things and wouldn't clog up the roads, seas, or airways.
Because the bricks could be traveling "in parallel," over many separate
routes at the same time, they'd probably arrive much quicker. This is
how packet switching works. When you send an email or browse the
Web, the data you send is split up into lots of packets that travel
separately over the Internet.
Protocols
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http://www.explainthatstuff.com/internet.html
The real Internet doesn't involving moving home with the help of envelopes—and the information that
flows back and forth can't be controlled by people like you or me. That's probably just as well given how
much data flows over the Net each day—roughly 3 billion emails and a huge amount of traffic
downloaded from the world's 250 million websites by its 2 billion users. If everything is sent by packetsharing, and no-one really controls it, how does that vast mass of data ever reach its destination without
getting lost?
The answer is called TCP/IP, which stands for Transmission Control Protocol/Internet Protocol. It's the
Internet's fundamental "control system" and it's really two systems in one. In the computer world, a
"protocol" is simply a standard way of doing things—a tried and trusted method that everybody follows to
ensure things get done properly.
So what do TCP and IP actually do?
Internet Protocol (IP) is simply the Internet's addressing system. All the machines on the Internet—
yours, mine, and everyone else's—are identified by an Internet Protocol (IP) address that takes the form
of a series of digits separated by dots or colons. If all the machines have numeric addresses, every
machine knows exactly how (and where) to contact every other machine. When it comes to websites, we
usually refer to them by easy-to-remember names (like www.explainthatstuff.com) rather than their actual
IP addresses—and there's a relatively simple system called DNS (Domain Name System) that enables
a computer to look up the IP address for any given website. In the original version of IP, known as IPv4,
addresses consisted of four pairs of digits, such as 12.34.56.78 or 123.255.212.55, but the rapid growth
in Internet use meant that all possible addresses were used up by January 2011. That has prompted the
introduction of a new IP system with more addresses, which is known as IPv6, where each address is
much longer and looks something like this: 123a:b716:7291:0da2:912c:0321:0ffe:1da2.
The other part of the control system, Transmission Control Protocol (TCP), sorts out how packets of
data move back and forth between one computer (in other words, one IP address) and another. It's TCP
that figures out how to get the data from the source to the destination, arranging for it to be broken into
packets, transmitted, resent if they get lost, and reassembled into the correct order at the other end.
Operating Systems
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The program that lets you interact with your
computer
It is software that communicates with the
computer hardware (acts like a translator)
Before you connect with the internet you
need certain software and hardware installed
on your computer
https://www.youtube.com/watch?v=pTdSs8k
QqSA&index=2&list=PL4316FC411AD077AA
Internet Service Provider (ISP)
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Companies that provide service to the
internet free or for a fee
Examples: BrightHouse, Century Link, AOL
Connecting to the Internet
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https://www.youtube.com/watch?v=hMX6dVa61t0
Internet Addresses
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The internet and the post office have similarities
The internet relies on an addressing system, like the
post office, to send data to a computer at a certain
destination
An Internet Protocol address (IP) is a number that
uniquely identifies each computer
All IP addresses used on the internet are
combinations of numbers instead of names
A domain name is the text version of an IP address
https://www.youtube.com/watch?v=qv0XCaUkfNk
Domain Names
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When you use a mobile phone and select
“mom’s home phone” from your address
book, you are actually dialing a combination
of numbers. This is how domain names work
with Web pages.
Domain Name Server (DSN)
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https://www.youtube.com/watch?v=3xnv-SGad5k
when you specify a domain name, a DNS server translates the
domain name to its related IP address so that information is
transmitted to the correct computer.
the right-side component of a domain name categorizes domains
into groups by company (.com), educational institution (.edu),
organization (.org) or country (for example, .ca). These
categories are called top-level domains (TLDs).
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each domain name is unique and registered with the Internet
Corporation for Assigned Names and Numbers (ICANN).
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when a name (for example, google) within a domain category (for
example, .com) is assigned, no other organization or individual
can use that name within that category.
Domain Names
The World Wide Web
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World Wide Web” and “Internet” are often used
interchangeably, but they are actually different.
The World Wide Web (WWW or Web) is a service of
the Internet.
And the Internet offers many services other than the
World Wide Web. These services include e-mail,
mailing lists, instant messaging, chat rooms, VoIP,
file transfers and newsgroups.
the World Wide Web consists of globally posted
electronic documents called Web pages, which can
contain text, graphics, links, audio, and video.
Web Browsers
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A Web browser is a software application that
enables your computer to retrieve and display
Web pages. The browser’s main function is to
present the Web resource that you choose by
requesting it from its server and displaying it
in your browser window.
https://www.youtube.com/watch?v=n8neFZw
d9eE
Most Common Web Browsers
Web Browsers
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the browser retrieves and displays a starting
Web page, sometimes called the browser’s
home page.
how long it takes for a Web page to load
depends on the speed of your Internet
connection and the amount of graphics on
the page.
https://www.youtube.com/watch?v=N5LQhuD
1FPY
The process of opening a web
browser
Web Addresses
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A Web page has a unique address, called a
Web address or URL (Uniform Resource
Locator). A Web browser retrieves a Web
page using the page's Web address. When
you enter a Web address in a browser, you
are requesting information from a Web
server.
http://www.cnet.com/Content/Reports
Servers and Clients
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all of the machines on the Internet can be
categorized as two types: servers and clients.
Those machines that provide services (like Web
servers or FTP servers) to other machines
are servers.
the machines that are used to connect to those
services are clients.
When you connect to Google at www.google.com to
do a search, Google is providing a server. You are
the client
A machine can be both a server and a client
File Transfer Protocol (FTP)
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The protocol (or instructions) for
exchanging files over the Internet.
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FTP is most commonly used to download a
file from a server using the Internet or
to upload a file to a server (e.g., uploading a
Web page file to a server).
Hyperlinks
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Web pages are also called hypertext
documents. Most Web pages contain links
that are built-in connections to other related
Web pages. A hypertext document is created
using Hypertext Markup Language (HTML),
which is a coding system that enables the
page developer to include hypertext links,
also called hyperlinks, in documents.
https://www.youtube.com/watch?v=qcjBrEvwI
E4
Downloading files from the
Internet
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http://www.gcflearnfree.org/internet101/4.6