Introduction to Dynamic Web Content

Web Application and the Request/Response Cycle

Web application is just like the application running on cloud server or remote server that we can access generally through port 80 or 443 for secure HTTPS connection. It is just like accessing a remote system using some Linux and connecting to some port of system. In case of web, the protocol, we use is HTTP and host name comes after it which may be local host in case of our own server and port will be 80 for HTTP and 443 for HTTPS connections. HTTP stands for Hyper Text Transfer Protocol and HTTPS stands for Secure Hyper Text Transfer Protocol.

The difference between HTTP and HTTPS is that data in HTTPS is encrypted by various cryptographic protocols which may be symmetric or asymmetric. So, if anyone will try to intercept traffic using tools like Wireshark in HTTPS, he/she will not be able to do so as he/she cannot read data. Now-a-days, almost all applications use HTTPS protocol for connecting to web servers. Moreover, using HTTPS it ensures that our passwords or usernames will not be leaked on the internet while transferring data to web application.

The Request/Response cycle is the same series of step we use to talk to someone on the phone call. It consists of following steps:

• Sever waiting for someone to call
• Client makes a call to server
• Server listens to client call
  
• Client requests data after establishing connection
• Server sending data to client
• Connection Closed and waiting for other client 

 Here below is shown the simple image of request response cycle so that you may get additional idea of how web application systems work.

 

Using Sockets to Make Network Connections with Python

A network socket is a software structure within a network node of a computer network that serves as an endpoint for sending and receiving data across the network. The structure and properties of a socket are defined by an application programming interface for the networking architecture. [Source].