What is the main difference between client-side and server-side development?

Client-side development and server-side development are two key aspects of web development, each with its own unique role and responsibilities.

1. Client-side Development: This refers to everything that the user interacts with on a website. It includes everything from the layout, design, and even some forms of data validation. The main languages used in client-side development are HTML, CSS, and JavaScript. The main difference here is that all the code runs on the user's browser.

2. Server-side Development: This is all about what goes on behind the scenes. It involves creating the logic that powers the website's functionality, managing databases, and ensuring that data is sent back to the client side correctly. Server-side development languages include PHP, Java, Python, Ruby, and .NET. The main difference here is that the code runs on the server.

In summary, the main difference between client-side and server-side development is where the code runs and what it's responsible for. Client-side code runs on the user's browser and is responsible for creating the interface that users interact with. Server-side code, on the other hand, runs on the server and is responsible for processing requests, interacting with databases, and sending data back to the client.