What's the difference between server-side and client-side optimization?

Server-side optimization happens on the web server before anything reaches your browser, while client-side optimization takes place right on your device, inside the browser. With server-side tweaks, you can improve things like page load times and backend performance. On the flip side, client-side optimization focuses more on user interface speed, like faster button clicks or smoother animations. Both aim to boost performance but from different sides of the fence.