My short indepth notes on web basics and https

The basics of web: 
www- collections of html documents
html- glues texts,images,videos together in a document
hyperlinks - A link between pages
urls - address to that document/web application
http - The main protocol of the web
web applications - Functionality driven web pages

Basic interaction pattern

HTML- Hyper text markup "LANGUAGE"
It is made up of

• text content  (What you see on page)
• markup (what it looks link behind the page)
• references to other document (eg: images + videos)
• links to other pages.

HTML Markup FORMAT

<TAG NAME> contents </TAG NAME>

eg:; <b>contents</b>. output will be contents i.e bolded format

HTML ATTRIBUTES FORMAT

<TAG NAME ATTR="VALUE"> contents </TAG NAME>

eg: <a href="www.google.com">search</a>.  <a> is anchor tag makes "seach"  clickable & links to google.com.

VOID TAG:

 It is a tag which has no closing tag "</TAG>"

ex: <img src="" alt="">, <br>

various important tags to play with are:

<img src="linktofile" alt="text">  eg: <img src="www.google.com/file.png" alt="image doesnt load">

<br>

<p></p> [it's also called block element cause it creates a invisible box around its contents]

<span class="CLASSNAME"></span> [it's also an inline element]

<div class="CLASSNAME"></div> [it's also an  block element]

<form> </form>

HTML STRUCTURE:

HTML Code

HTML Structure

URL: Uniform resource locator

URL Structure

URL Query parameters(GET parameters)

ex: http://www.example.com/foo?p=1&q=neat # fragment

after ?, all are query parameters(p=1, q=neat)

& is used to seperate from each query parameters.

after # all are fragments and are not sent to server but exists with in a browser.

PORT:

ex: http://www.example.com:80/foo?p=1&q=neat # fragment [here 80 is the port comes before path]

or   http://localhost:8080/path [here 8080 is the port comes between host and path in a url ]

HTTP:

request line and headers.

Request line for the above url

Headers format is in green and most used headers are in red

http server response.

http server response and meaning of its different status code

Telnet request from user and its response from server

IF we type request line we will receive response in following format

SERVERS:

Server responds in two ways depend on readiness of its content

• Static
• Dynamic

Server Responds to client in either of the two ways.

Example: your facebook page and google search results are dynamic. were as this blog page is static one.

Source: These notes were gathered as important from the web development course on Udacity.