Google Developer Student Clubs
Web Development Workshop
Day 1
Basics Of HTTP
Client Server Architecture
URL
(Uniform Resource Locator)
URL is address of a resource on the World Wide Web
https://github.com/TisheelDomain
Protocol
Endpoint
HTTP
(Hyper Text Transfer Protocol)
Hypertext Transfer Protocol (HTTP) is an application-layer protocol for transmitting hypermedia documents, such as HTML. It was designed for communication between web browsers and web servers, but it can also be used for other purposes. HTTP follows a classical client-server model, with a client opening a connection to make a request, then waiting until it receives a response.
Client-Server Architecture
# Clients always initiate communication sessions with servers
How HTTP works ?
Client
Server
HTTP Request
HTTP Response
GET /home.html HTTP/1.1
Host: developer.mozilla.org
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:50.0)
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Connection: keep-alive
Upgrade-Insecure-Requests: 1
If-Modified-Since: Mon, 18 Jul 2016 02:36:04 GMT
200 OK
Access-Control-Allow-Origin: *
Connection: Keep-Alive
Content-Encoding: gzip
Content-Type: text/html; charset=utf-8
Date: Mon, 18 Jul 2016 16:06:00 GMT
Last-Modified: Mon, 18 Jul 2016 02:36:04 GMT
Server: Apache
Request Header
<html>
<head>
<title>Home</title>
</head>
<body>
<h1>Hello World</h1>
</body>
</html>
Response Header
| HTTP Methods | HTTP Status Code |
|---|---|
| GET - retrieve data from server | 100 - 199 information responses |
| POST - submit data to server | 200 - 299 successful responses |
| PUT - save data to location | 400 - 499 client error responses |
| DELETE - delete data from location | 500 - 599 server error responses |
HTTPS (HyperText Transfer Protocol Secure)
Hypertext Transfer Protocol Secure (HTTPS) is an extension of the HyperText Transfer Protocol (HTTP). It uses encryption for secure communication over a network, and is widely used on the internet. In HTTPS, the communication protocol is encrypted using Transport Layer Security (TLS) or Secure Sockets Layer (SSL).
https://github.com/Tisheel
20.207.73.82
ROUTER
| Domain | Ip Address |
|---|---|
| github.com | 20.207.73.82 |
| rnsit.ac.in | 45.113.122.159 |
| ... | ... |
Domain Name Server (DNS)
20.207.73.82:443
TCP/IP
Transmission Control Protocol/Internet Protocol (TCP/IP) is a networking protocol that allows two computers to communicate.
Sender
Sender
Receiver
Data Segments
Data Segments
IP
TCP
TCP