- With the help of these protocol information or data of particular website is exchanged between web server and web browser.
- HTTP is stateless protocol.
- HTTP is client - server protocol.
- Request sent by one entity, the user agent (or proxy)
- Most of the time User Agent is a Web Browser.
- HTTP is stateless but not sessionless
- The use of Cookies allows the use of stateful session
-
Example: Using E-Commerce shopping basket where we need continuos session.
- Client:
- The user agent is any tool that acts on the behalf of the user .
- The browser is always the entity that initiating the requests.
- Server:
- A server appears as only a single machine virtually, thet is because it may actually be a collection of servers.
- Proxies:
- Between the web broweser and the server numorous computers and machines ralay the HTTP message those operating at the application layer are generally called proxies.
- Proxies can perform Following Task:
- Caching : Like History, browsing cache...
- Filtering : Like an antivirus scan..
- Load Balancing : To allow multiple server to serve the different request.
- Authentication : To control access to different resources.
- Logging : Allowing the storage of historical information.
| HTTP | HTTPS |
|---|---|
| URL begin with http | URL begin with https |
| Insecured | Secured |
| Works at Application Layer | Works at Transport Layer |
| Encryption is Absent | Encryption is Present |
| Does not require any certificate | It need SSL certificate |
| Uses Port 80 | Uses Port 443 |
In the next Day 18 we will see about SSL.