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Start your OWN web page - How the WWW Works
BASIC
WWW - World Wide Web
-it is just a term.
The WWW as an entity doesn't really exist!
It's just a collection of networked computers, internet connections, services and servers
with lots of html files and images to view and share, and client-side browsers you use to
view them.
But when you put them all together, it's magic!
INTERNET - collection of networked or "connected"
computers.
HTTP - Hyper Text Transfer Protocol, this is a formal description of how computers interact with each other on the internet.
ISP - Internet Service Provider, this is
YOUR connection to the INTERNET via a modem.
BROWSER - this is the application you use to read or display
the contents of html files.
Netscape is a company name, not a browser!
Netscape's browser is called Communicator
Microsoft's browser is called Internet Exployer.
Browsers are FREE applications. Why?.. because both Netscape and
Microsoft also sell SERVERS and applications used to create and
edit web pages.
HTML - Hyper Text Mark-up Language, this is the programming language that creates files that can be read or opened using a browser. ie:filename.html
SERVER - this is the hardware and software that allows one computer to connect to another computer. A server is a program that knows a language or protocol for communication.
URL - Uniform Resource Locator, this is
the INTERNET address to a home page which is located on a SERVER,
which is also connected to the internet.
Example: http://capoferri.com
HOME PAGE - this is the html file(named
index.html) that is displayed in a browser when someone enters the URL in the browser
"location" text editing box.
HOW IT ALL HAPPENS!
When you are connected to the internet through YOUR ISP and enter in YOUR
BROWSER, http:// YOU ARE SAYING,
"interact with my computer and use the Hyper Text Transfer Protocol." Then you
must enter the address or URL that you wish to interact with. Try it, you
do not need to enter www. In fact, with the latest versions of Communicator
and Internet Exployer browsers you are not
required to enter http:
A
LITTLE MORE TECHNICAL
HOW THE INTERNET WORKS !
The INTERNET is known as a client-server system using the HTTP
(Protocol). Your web BROWSER is the client; the
remote computer which stores the data is the SERVER. Your computer
has requested a filename.html from a SERVER . This server
sends the file you've requested over the Internet--a collection of networked computers--to
your computer. Your web browser interprets the file and displays it on your computer
screen.Very simple!!
ISP - Internet Service Provider, once
upon a time, you could only connect to the Internet if you belonged to a major university
or had a note from the Pentagon. Not anymore: ISPs have arrived to act as your
user-friendly front end to all that the Internet offers. Most ISPs have a network of
servers (mail, news, Web, and the like), routers, and modems attached to a permanent,
high-speed Internet "backbone" connection. Subscribers can then dial into the
local network to gain Internet access--without having to maintain servers, file for domain
names, or learn Unix.
PROTOCOL - this is the formal
description of how computers interact with each other.
"HOST" SERVER -
this is the server where your web files reside; each URL resides on a server.
FULL URL PATH - this is the URL of any file ie:
http://yourname.com PLUS the filename.
ie: http://yourname.com/pageone.html
FULL URL PATH - this is the URL of any file ie:
http://yourname.com PLUS the folder name and the
filename ie: http://yourname.com/images/imageone.gif
INDEX.HTML - this is the
filename that is displayed in a browser when someone
enters the URL in the browser "location" text editing box. The same as
HOME PAGE.
SEARCH ENGINES - a free service that searches
html files on host servers and "looks for" the meta tags that match the user's
search request. But only IF the URL is included the search engine's data base or if a
"robot" or "spider" used by the search engine finds the meta tags in a
html file. The engine will then "return" the URL or the FULL PATH to a
html filename as a link.
DO NOT GET CONFUSED!! If you
know the URL, to a HOME PAGE (the index.html).
YOU DO NOT NEED A SEARCH ENGINE.
Now think about this...a search engine will display a link to a html file. This
file could be pageone.html and NOT your URL or HOME PAGE (index.html).
LOCAL ISP - normally a service that provides you JUST
a connection to the internet. Fees are +/- $12.00 per month.
GATEWAY ISP - a service that provides a
connection to the internet AND additional services that in most cases you
can get for FREE . AOL is a gateway; fees are normally DOUBLE
the price of a local ISP. The gateway will provide you a browser, modified versions of
Communicator or Internet Exployer, plus they are continually up-loading files to YOUR
computer every time they come up with an additional service, regardless if you want it or
not. AOL also SELLS
your e-mail address and your personal information.
"HIGHLY TECHNICAL"
DOMAIN NAMES - are a way of dividing up
all the URLs in the WORLD so each one can have a unique NAME that's easy for people to use
because it's made of words, not numbers.
InterNIC - is the organization
that controls and manages DOMAIN NAMES and IP#s.
When YOU register YOUR DOMAIN NAME (yourname.com) with InterNIC, for a $35.00 per year
fee, you are assigned a number called IP# that is equal to your domain name, and no one
can use your domain name or IP number.
*What this means is after you have a IP# (domain name) you can transfer your web files to
another server. This MUST be completed through InterNIC because you are changing the
IP number of the HOST SERVER, after InterNIC up-dates the data base you then PUBLISH your
files to your NEW HOST SERVER.*
HOW THE INTERNET REALLY WORKS !
The INTERNET is known as a client-server system
using the HTTP (Protocol). The web BROWSER is the client;
the remote computer which stores the data is the SERVER.
Whenever a surfer enters a URL (yourname.com) in the BROWSER, InterNic converts that
name to the SERVER IP number of the SERVER. The surfer is directed to that SERVER,
and then re-directed to the yourname.com IP# folder on that server. The server sends the
file over the Internet to the surfer's computer. The web browser interprets the file and
displays it on the computer screen.
Very simple!!
The web server is a program running on a networked machine, waiting for connections from
the outside world to serve certain documents on behalf of a request by a browser. To
communicate, the server and the browser use an asynchronous communication method called
the HTTP (hypertext transaction) protocol. It works as follows:
1) The user starts the browser and types in an URL
2) The browser connects to the given host and requests the specified document.
3) The web server handles the request and sends out a response:
if this document exists, the web server delivers it, if it does not exist or if access is
not permitted, the web server sends back an error message instead.
The document delivered as an answer to this request may contain inline objects. Inline
objects are simply URLs pointing to another resource, either a document, an image, an
applet, a video/audio stream, or any other addressable HTML object. The browser then
requests all inline objects of the current page from the server using the steps 2 and 3
above, before it can display the content of that page.
This communication method is called asynchronous, because the browser sends out many
requests for inline documents at once (without waiting for a response from the server
before sending the next request) using different communication channels: Since the
browser's requests are often handled by different server processes or different threads of
a server process, there is absolutely no relationship between the logfile entries caused
by the responses from the server due to a request of a document and it's inline objects.
For example, the order in which the server logs the successful transmission of the
document itself and the inline images contained therein is not predictable and depends on
the type of documents, objects, server speed, system and network load, and many other
parameters.
META TAGS - these are "key words" that best
describe your html file or files. These tags DO NOT DISPLAY in a browser.
HTML EDITOR - this is an application that creates and edits html files.
PUBLISH - the term used when web page files are transferred or copied from a computer's hard drive (ie:my computer) to the host server. After publishing, your html files are available to the internet.
HTTP - Hyper Text Transfer Protocol, this
is a formal description of how computers interact with each other on the internet.
FTP - File Transfer Protocol, this is a
protocol that allows transfer only of files from a computer to a server or another
computer.
GOPHER - Protocol, a system of displaying
information on the Internet in a"menu" format popular before the emergence of
the World Wide Web and Web browsers. Although still available,Gopher software is barely
used at all today.
STMP SERVER-Simple Mail Transfer Protocol, this
is a formal description of how computers interact with each other. This is one way you
send and receive e-mail.
MAILTO - Protocol, enables you to send messages around the
internet using a browser.
POP 3 - Post Office Protocol a send/receive e-mail protocol.
NEWS - Protocol, used for visiting and posting to newsgroups
around the internet.
TCP/IP - Transmission Control Protocol /
Internet Protocol this is the protocol used by many home computers to connect to
an ISP; it is the "dial up icon" on your desktop or the "My Computer"
icon on the desktop - Dial Up Network.
T1-T3 - These labels refer to the speed of the connection
from the host server to the rest of the Internet. Each is a type of connection leased from
the phone company. T-1 can carry data at 1.5 million bits per second (bps) and is the
fastest speed commonly used to connect a network of servers to the Internet. At maximum
capacity, a T-1 line could (theoretically) move a megabyte of data in less than 10
seconds. The less common but more powerful T-3 connection can carry data at 44.7 million
bps--more than enough to do full-screen, full-motion video. Because cost probably isn't
the only concern, pay close attention to the available "bandwidth" or
"throughput." Bandwidth is a measure of how much data your visitors download.
Bandwidth allowance refers to the amount of data that can be transferred from your site
each month and typically does not include the upload and retrieval of your pages via FTP.
To calculate roughly how much bandwidth you need, multiply the size of your largest page
(including all the graphics) by the number of visitors you think your site will get each
month. If your largest page
is 90Kb, for example, and you expect 1,000 visitors, you require 90MB (90,000Kb) just for
that page alone. If you figure that each visitor will visit an average of five pages on
your site, you're looking at using about 450MB of bandwidth each month. If you were to
double any one of those factors (the number of visitors, the number of pages each visitor
is likely to view, or the size of your largest page), you're looking at nearly a full
gigabyte of bandwidth. (A gigabyte is 1000MB.) In addition to bandwidth, you also need to
pay close attention to the amount of space you're allowed. ISPs and hosting companies
provide a certain amount of space for the storage of your HTML pages and all the related
graphics--typically a minimum of 10MB. Be sure you're renting enough space to store all
your pages and to allow room for growth.
ROUTERS - these are SERVERS that act as "traffic
cop" computers on the internet backbone, responsible for re-directing data from
sender to receiver. North America has twenty-eight routers and +/- 50 other routers in the
rest of the world. Sometimes when you receive an error message "unable to find or
connect" this message is coming from a router, not your ISP, not the HOST SERVER.
ENCRYPTION - (a feature within a browser)
What is 40 bit and 128-bit encryption, and how does it work?
Encryption is a sophisticated scrambling method that is designed to prevent unauthorized
eavesdropping on electronic data. Encryption works by taking a piece of information, and
processing it with a mathematical formula (called an "algorithm") that converts
the information into a meaningless string of letters and numbers.
For example, the sentence "This is a secret" when cryptic may look like
"as03xx1a79x!dqt.". This encrypted string of information can be sent over the
Internet with the likelihood that anyone intercepting the message would not be able to
comprehend it. When the string does reach its intended destination, a similar mathematical
formula is applied to the string to decrypt it. A128-bit encryption refers to the size of
the key used to encrypt the message. A longer key means the encryption is more
"random", and someone attempting to decipher the message would have to try more
combinations of keys. Each extra bit in a key doubles the complexity of the key.
HTML file- Just what is it?
*BASIC*
Hyper Text Mark-up Language, this is the programming language that creates
files that can be read or opened using a browser. ie:filename.html
Html files CAN BE created using a simple ACSII text editor like Windows
Note Pad!
It is very difficult because you must know about 1000 commands or
instructions called "tags". A html WYSIWYG editor will create the tags. Html
editors look just like a word processor!
Each instruction must have a start tag and a end tag. If you want to make some text
bold, the tags are: <b>Make this text bold</b>
The <b> is the start tag, the </b> is the end tag.
The results will look like.... Make this text bold
Images can be included in a html file, they MUST be in the jpg or gif format.
*"HIGHLY TECHNICAL STUFF"*
E-mail forms can be included in a html file.
Java Script can be included in a html file.
Java *.class files can be included in a html file.
CGI can be included in a html file.
SSI can be included in a html file.