for protocol application layer uses HTTP as their protocol and Web Browser as their software.

In client-server, client always request and server provides. Here a central and dedicated server will be noticeable. Client first request for data, server authenticate the client the provides the data.

On P2P, client sometimes becomes servers and servers sometimes becomes client. Two or more computer share resources without having any central server.

A web page or webpage is a document that is viewed in an Internet browser. A web page consists of objects like HTML file, JPEG image, Java applet, audio file.

URL spec

What happens when we entered an URL? → after pressing enter using HTTP, the server gets hit. Then the server response. So there is two kind of message one is HTTP request message and another one is HTTP response message.

1. HTTP request message →

   1. Method → GET, POST, HEAD

      

      

   2. URL → URL of the website

   3. sp → separator

   4. version → http version

   5. cr → line ended

   6. if → go to the next line both cr and if combination make represents to go to the next line.

   7. header field name → extra information like what web browser using, what type of data looking for, what language the website should be in.

   8. entire body → form or other infos

      

2. HTTP response time →

   1. version → HTTP version
   2. status code → error or request successful code.
   3. phrase → code er por jeita thake . 200 is the code and OK is the phrase.

https://developer.mozilla.org/en-US/docs/Web/HTTP/Status

When GET method used as POST method? it is used in URL method. for example google search, if you typed something in the google search it becomes URL and it can be noticed in the URL link of the google search result link. Here you are posting your search term to get the data it needs.

What type of request are in there and explain

HTTPS - Secure version of http. Provides transport layer security. Needs to install signed SSL. This SSL contains information about the organization that will help to authenticate and it also contains cryptographic information that will help the user to communicate securely. it also providrs some SEO advantages. HTTPS transports data using 443 port.

Here's a breakdown of the major differences between the versions:

1. HTTP 1 : Has get, post, head method. Has persistent commection and pipe-lining. Has headers, multi type content and status code. Problem - it uses first come first server scheduling which cause HOL issue which is small object wait behind large object.
2. HTTP2: it mitigate HOL blocking by introducing multiplexing. binary protocol instead of text based protocol. Server push: servers can send resources to a client proactively. Stream prioritization: Allows clients to prioritize requests, letting the server know the order in which the client prefers to receive responses. Problem: No security over vanilla TCP connection.
3. HTTP3: It is built on QUIC which reduces latency and via integrated transport and security protocols. Supports changes in the client's network connection (e.g., switching from Wi-Fi to cellular) without needing to restart sessions.