In web development, client-side and server-side refer to the location where certain tasks or processes are carried out in a web application. Client-side refers to processes that are executed on the users device, while server-side refers to processes that are carried out on the web server where the website or web application is hosted. Client-side processes have less access to resources and are less secure, while server-side processes have more access to resources and are more secure. Client-side processes include running scripts on the users computer without involving any processing on the server, while server-side processes include tasks such as retrieving data from a database, rendering a web page, or handling user input. Understanding the difference between server-side and client-side processes is important for web developers who want to create high-quality web applications that are efficient and effective, and that provide a good user experience.