What is code splitting, and how is it different from lazy loading?

Code splitting breaks JavaScript into smaller bundles. Lazy loading defers loading a part until it's needed.

Example: a heavy editor doesn't need to weigh down the initial view when most people never open it.

To be precise: Next.js splits code for you, and dynamic imports give you extra control over loading components and libraries.

Pitfall: splitting code alone doesn't prove better performance. I check whether less JS is downloaded and run up front, and that the user doesn't then wait too long for the part they need.