Week 9 - Networking and APIs

Introduction to Networking

Client Server Model

TCP/IP Protocol

HTTP Protocol

URL Format

Web APIs

API Testing Tools

Using APIs

Practice

Assignment

Core program

The Client-Server Model

The client-server model is a fundamental design pattern for distributed computing. Here, we will focus here on how it is typically used for web applications where it is the interaction pattern used every time someone visits a website or uses an online service.

Let's say you log in to your online bank account:

As the client, you want to see the amount of money you currently have. The browser sends out a request to the server, who then activates the necessary services (in this example, some kind of database) and returns with a response containing the exact amount of money you currently have in the bank.

The Client-Server Model divides roles between two entities:

1. The Client (The Requester):
   • Typically your web browser (Chrome, Firefox) or a mobile app.
   • It's the device that initiates the communication.
   • It requests a service or resource (e.g., "Give me the content for https://hackyourfuture.net").
2. The Server (The Provider):
   • A powerful computer, often located in a data center, that is running a server application and is connected to the Internet.
   • It listens for requests from clients.
   • It processes the request and sends a response back (e.g., "Here is the HTML, CSS, and JavaScript for https://hackyourfuture.net").

The video below explains it well:

https://www.youtube.com/watch?v=L5BlpPU_muY

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