This is
a quick reference guide for HTML in 1 hour. Keep learning the tags and
simultaneously execute them in the browser to see the effect.
<B> - Bold ex. <B>Hello World
<em> - Italic ex. <em>Hello World<em>
<a> - Anchor// For adding links ex. <a href= “www.yahoo.com”>yahoo</a>
<P> Paragraph//Gives spacing b/w paragraphs ex. <P>Hello World</P>
#fragment // purely exists in the browser. ex. url#fragment
?query parameter
Void tags
They haveno content so they does not involve closing.
<img> Image
//For adding images ex. <img src=”reference url” alt=”text
if img not there”>
<BR> Break ex. Hi dude<BR>How are
you?
Inline & Block
<P> tag
considers the statement as a block.
It has height and width.
whereas as; <BR>
tag is inline and only changes the line.
All elements we have studied here are inline except <P>
tag.
<SPAN> Inline ex.
<span class=”foo”>text</span>
<DIV> Block ex<div
class=”bar”>text</div>
Other Inline tags are:
<a><span><br><img><strong>
localhost is the name of the machine and 8000 is the port
no. In order to make an internet connection you need two things.
1. Address of the machine
2. Port No.(Bydefault port is 80). If you want to
change it, you can change it between url and path.
A postmortem of an address:
host- www.google.com
protocol - http
fragments - #blue
query - ?p=foo
port- 80
General HTML Document Structure
<!DOCTYPE HTML> //document
type
<HTML> //contains
kind of metadata
<HEAD>
<TITLE></TITLE> //title
of the page in the window of the browser
</HEAD>
<BODY>
<B>contentssssss</B> //body of the
page i.e. actual contents of the page
</BODY>
</HTML>
HTTP Response Headers:
Date- Tue, 20 Jan
2012 07:33:33 GMT
Server – Apache/2.2.3 (This is version no. Its kept
secret or it’ll make it vulnerable to attacks.)
Content- Type:
text/html (Type of document to
be returned and told to the browser.)
Content- Length: 1539
Creating a connection:
telnet www.yahoo.com 80 (browser makes request)
GET / HTTP/1.0 (In 1.1, the
server does not closes the connection by default to allow browser to make
multiple requests to the server. Connection remains open and is a little pain
if we are using telnet. 1.0 is an optimisation. )
Host: www.yahoo.com (google wants this because its
hosting a lot of different things.)
GET method:
1. GET : a method which tells what type of requests
you are making to the server. Other method are POST
2. /foo: tells about the path. This tells abot the
requested document to the server. Path is used for making the request.
3. HTTP/1.1: Mostly used nowadays.
Request Line to GET this URL is: GET foo/logo.png?p=1
HTTP/1.1
Fragments are never sent to the server. They purely stay in
the browser or in the client side.
URL’s stands for uniform Resource Locator ex. http://www.yahoo.com/finance
So http is a protocol; www.yahoo.com
is a host name or domain name. Its translated into IP address; /finance is a
path. Also it can be very large also. We can have minimum path as /
An important point about URL is that they are case
sensitive.
TELNET Request
Status code: 302/200 etc.
Location: http://www.iana.org/domain/example
Request made is:
GET /domain/example HTTP/1.0
Purpose of Servers
is To respond to HTTP requests. There are two type of
responses made by the server:
1. Static:
Pre written files ex. Image files
2. Dynamic:
made on the fly i.e. during the execution of the program. Used mostly nowadays.
Web Application does this dynamic work. It lives on a server
and responds to the browser HTTP requests. Ex. Your facebook page; A blog front
page; Google search results.
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