Sunday, July 11, 2010

Tag Attributes and STYLES

 Heading Attributes < H1 >

ALIGN=“LEFT”
ALIGN=“CENTER”
ALIGN=“RIGHT”
ALIGN=“JUSTIFY”

Ex.
< H1 ALIGN=“CENTER” > Center Heading< /H1 >
< H1 ALIGN=“RIGHT” > Right Aligned Heading < /H1 >

ORDERED LIST Attributes < OL >

TYPE=“A”
TYPE=“a”
TYPE=“I”
TYPE=“i”
TYPE=“1”
START=n
 

Ex.
< OL TYPE=“A” >< /OL >
< OL START=51 >< /OL >



UNORDERED LIST Attributes < UL >


TYPE=“DISC”
TYPE=“SQUARE”
TYPE=“CIRCLE”

Ex.
< UL TYPE=“SQUARE” >< /UL >
< UL TYPE=“CIRCLE” >< /UL >





PHYSICAL CHARACTER STYLES
< blink >< /blink > - makes the text blink
< B >< /B > - Applies Boldface to text
< I >< /I > - Applies Italics to Text
< TT >< /TT > - Applies a fixed width font
< U >< /U > - Applies underline to text
< SUB >< /SUB > - Formats text as subscript
< SUP >< /SUP > - Formats text as superscript
< SMALL >< /SMALL > - Makes the text smaller
< BIG >< /BIG > - Makes the text bigger
< STRIKE >< /STRIKE > - Creates a strikethrough to text
< B >< I >< /I >< /B > - Applies boldface and italics to text
< BIG >< TT >< /TT >< /BIG > - Applies fixed-width font and makes the text bigger
< SMALL >< I >< /I >< /SMALL > - Applies Italics and makes text smaller
< FONT COLOR="GRAY" >< /FONT > - Applies color to font
< DEL >< /DEL > - Creates a strikethrough to text
< INS >< /INS > - Applies underline to text



Examples:
< H1 >Physical Character Styles< /H1 >
< blink >Blinking< /blink >< br >
< B >Bold< /B >< BR >
< I >Italic< /I >< BR >
< TT >Teletype (Monospaced)< /TT >< BR >
< U >Underlined< /U >< BR >
Subscripts: f< SUB >0< /SUB > + f< SUB >1< /SUB >< BR >
Superscripts: x< SUP >2< /SUP > + y< SUP >2< /SUP >< BR >
< SMALL >Smaller< /SMALL >< BR >
< BIG >Bigger< /BIG >< BR >
< STRIKE >Strike Through< /STRIKE >< BR >
< B >< I >Bold Italic< /I >< /B >< BR >
< BIG >< TT >Big Monospaced< /TT >< /BIG >< BR >
< SMALL >< I >Small Italic< /I >< /SMALL >< BR >
< FONT COLOR="GRAY" >Gray< /FONT >< BR >
< DEL >Delete< /DEL >< BR >
< INS >Insert< /INS >< BR >



HORIZONTAL RULE Attributes



SIZE=n         Specifies rule height (in pixels)
WIDTH=n        Specifies rule Length (in Pixels)
WIDTH=“n%”    Specifies rule length in percentage
ALIGN=LEFT    Specifies Left Alignment
ALIGN=RIGHT    Specifies Right Alignment
ALIGN=CENTER    Specifies Center Alignment
NOSHADE        Specifies that rule has no shading



EX.

< HR WIDTH=“80%” SIZE=8 >
< HR WIDTH=“50%” >
< HR WIDTH=400 ALIGN=RIGHT >
< HR NOSHADE ALIGN=CENTER WIDTH=200 >

Ordered, Unordered and Definition List (HTML)

There are three types of lists in HTML:

Ordered Lists
These are sometimes called numbered lists, and list items that have a specific numerical order or ranking.

Unordered Lists
These are sometimes called bulleted lists, because they have small bullet icons in front of the list items. They are for lists that don't have a required order.

Definition Lists
These are lists of items that have two parts, a term to be defined and the definition.

Ordered Lists
Use the < ol > tag (the ending < /ol >
tag is required), to create a numbered list with numbers starting at 1. The elements are created with the
< li > tag



When to use ordered List:
Use ordered lists anywhere you want to show a specific order for the list items to be followed, or to rank items sequentially. These lists are most often found in instructions and recipes.




Unordered Lists
Use the < ul > tag (the ending < /ul > tag is required) to create a list with bullets instead of numbers. Just like with the ordered list, the elements are created with the < li > tag.



When to use unordered list:
Use unordered lists for any list that doesn't have to be in a specific order. This is the most common type of list found on a Web page.




Definition Lists
Definition lists create a list with two parts to each entry: the name or term to be defined and the definition. This creates lists similar to a dictionary or glossary. There are three tags associated with the definition list:

< dl > to define the list
< dt > to define the definition term
< dd > to define the definition of the term

*HTML does not require the closing tag for the < dt > or the < dd >, but it's a good idea to use them so other parts of your design aren't confused.





When to use Definition list.
Use definition lists anywhere you have a list that has two parts to each item. The most common use is with a glossary of terms.





< BR >, < P > and < HR > TAGS

< BR > tells your browser to go to the beginning of the next line. BR stands for line BReak. < BR > acts in the same way as the ENTER key on your keyboard. When you press the ENTER key, the cursor goes to the beginning of the next line. With < BR >, the browser is also told to go to the beginning of the next line. Remember that when you save an HTML document, you are saving it as TEXT ONLY which means that no codes are saved and so your browser will not know when to end a line and continue on to the next line. The  < BR > tag does this for you.

< P > for Paragraph tells your browser to insert a blank or empty line and then begin a new line (a new paragraph). < BR > tells the browser when a line has ended while
tells the browser to leave a blank line and begin a new paragraph.

< HR > puts a line across the page. HR stands for Horizontal Rule. The two lines you see below were put there with < HR > tags.

What is HTML

HTML is a language for describing web pages.
• HTML stands for Hyper Text Markup Language
• HTML is not a programming language, it is a markup language
• A markup language is a set of markup tags
• HTML uses markup tags to describe web pages
________________________________________
HTML Tags
HTML markup tags are usually called HTML tags
• HTML tags are keywords surrounded by angle brackets like < HTML >
• HTML tags normally come in pairs like < b > and < /b >
• The first tag in a pair is the start tag, the second tag is the end tag
• Start and end tags are also called opening tags and closing tags
________________________________________
HTML Documents = Web Pages
• HTML documents describe web pages
• HTML documents contain HTML tags and plain text
• HTML documents are also called web pages
The purpose of a web browser (like Internet Explorer or Firefox) is to read HTML documents and display them as web pages. The browser does not display the HTML tags, but uses the tags to interpret the content of the page:

Wednesday, June 23, 2010

History of the internet

How the Internet came about
The foundations of the Internet were formed when packet-switching networks came into operation in the 1960s. Transmitted data is broken up into small packets of data, sent to its destination, and reassembled at the other side. This means that a single signal can be routed to multiple users, and an interrupted packet may be re-sent without loss of transmission. Packets can be compressed for speed and encrypted for security.

Computers at the time were massive, primitive structures. The only type of network in operation before was made up of terminals that logged into mainframes. This is similar to the present-day client/server relationship we have with the modern Internet, except the computers are usually comparable in terms of power, and so the Internet is known as a peer-to-peer system.


ARPANET and onwards
Early packet-switching networks were set up in Europe. Development of a similar system began in America in 1968, and went into operation the year after in the US Defence Department's Advanced Research Projects Agency (ARPA). The ARPANET used Network Control Protocol as its transmission protocol from 1969 to 1982, when NCP was replaced with the now-widespread TCP/IP.

Now that the technology was in place, strategies were put forth on what to do with it. Eventually, the first large-scale Internet was created — a set of interconnected US military computers. The idea was simple: if an attack was laid down on one part of the system, the rest of the system would still be operational enough to blow the hell out of whoever was attacking the country. Alternatively, losing the mainframe in a centralised system would spell disaster. This was during the height of the Cold War, and the inevitable nuclear war looked very close to happening.

Services like Email found their first usage through the ARPANET system, and its obvious benefits were lauded by all who participated. The popular bulletin-board system, Usenet, was developed between the 70s and 80s. Around this stage all of the main universities in the US were connected to the network and used it for transmitting experimental data and educational resources. It was found to be an excellent method of sharing information. In 1973 the first international (and indeed intercontinental) connection was made to the University College of London in England.


The rise of USENET
USENET contributed more than anything else to the way the Internet began to take off. The spirit of information sharing and discussion that is the hallmark of the net was encapsulated in this system. Usenet is considered to have begun in 1979, and went through a few revisions. In an early triumph for freedom of speech, the restrictions on taboo subjects like recreational drugs were circumvented by independent people setting up their own servers and hosting discussions there instead of on the main ARPANET servers, where this was forbidden. New transmission methods were developed, the standard becoming NNTP (Net News Transfer Protocol), which is still in use today.
The introduction of personal computers in the late 70s brought a large new audience to the developing Internet. They used email and participated in discussions on networks like Usenet, Bitnet and Fidonet, which eventually were all joined together. The Internet was growing exponentially. IRC (Internet Relay Chat) became available in 1988 and communities formed in chat rooms.


World-Wide Web unleashed
It was only in 1991 that what we now call the World-Wide Web was introduced, developed by » Mr. Tim Berners-Lee, with assistance from Robert Caillau (while both were working at » CERN. Tim's now a member of the » W3C). Tim saw the need for a standard linked information system accessible across the range of different computers in use. It had to be simple so that it could work on both dumb terminals and high-end graphical X-Window platforms. He got some pages up and was able to access them with his 'browser'.

Quickly researchers got interested and started designing web sites and browsers. In 1993 the first proper web-browser, Mosaic, took the Internet by storm; having been developed at the National Center for Supercomputer Applications (NCSA). As soon as it was ported to PCs and Macs it immediately effected a boom in web usage.
Quickly services were set up for domain registration and sites began turning up on the web, running on very basic HTML. Even at this stage, malicious viruses and worms were infiltrating computers connected to the Internet. The web had an incredible 341, 634% annual growth rate. Important sites like the White House and Pizza Hut appeared. Online shopping sites showed up. The www was quickly the most popular service on the Internet. It was around 1995 when the first large ISPs like AOL and CompuServe began offering Internet access to the masses. Technology like Sun's Java and search engines are released. The somewhat legendary browser war was in full swing between Netscape and Microsoft, with new browser releases coming every month and the web becoming increasingly fragmented. Despite this, the public's enthusiasm for the Internet went unbridled.

Today, in whatever year this is, the web is still growing at an amazing rate. Technology has improved considerably, and the web is regarded as an indispensable tool for education, business and entertainment. There are billions of pages on the web, with thousands more being added every hour. The Internet is a system that is nigh-on impossible to destroy, and looks set to become an ever-larger influence on the world in the future.

________________________________________
What is the Internet?
The Internet today is a large-scale network of millions of computers that allows continuous communication across the globe. The various applications of the Internet are:
• The World-Wide Web (the web or WWW)
• Electronic Mail (E-Mail)
• File Transfer Protocol (FTP)
• Internet Relay chat (IRC)
• USENET (a news service)

The World-Wide Web
The www is the reason the Internet has become as popular as it has. This is the part of the Internet that the majority of users see — the websites and the pages that make them up. The web is the most widely used service of the Internet, accessed through a web browser like Internet Explorer or Netscape Navigator. These pieces of software are gradually integrating other parts of the Internet into them (most notably email and ftp), so that eventually we will have one interface to the entire array of services the Internet offers.

The web is an immense collection of web pages, linked together with hypertext links. Thousands of new pages of information are added to the heaving web every hour. Each page is placed on a server, a computer continually connected to the rest of the web. The information is then available to anyone else with access to the Internet. Web pages can have a mixture of text, graphics and multimedia. Nowadays, there's information on practically anything you could be interested in available somewhere on the web. You can use a search engine to find what you want.


E-Mail
Electronic Mail works in much the same way as traditional mail (now charmingly labelled 'snail-mail') does. Anyone is allowed to sign up for an email address and then people can send you messages, or attach files from their computer and send them too. The main benefit of email is the close to instantaneous delivery of messages that occurs. You can send an email to the other side of the world and it will arrive in less than a minute. You can also sign up to weekly newsletters and have information you want delivered right to your computer.


File Transfer Protocol
While web pages are transferred between computers using the http protocol, other types of files are sent using FTP. People can share files, like music and videos, among each other and the rest of the world by uploading them to a server and allowing others to download them to their own computers.
Internet Relay Chat
IRC is a service that allows you to connect to your chosen channel and talk in real-time to people with the same interests as you. You can download » mIRC and start chatting right away.


USENET
USENET (Unix User Network) is a system of bulletin boards where you and anyone else can post messages and people will read and reply to them. As with IRC, you will find boards set up for all sorts of groups of people. The search engine » Google has set up a web-interface for these discussion boards.