What's the difference between a website and a web application?

Websites are made up from many different pages.
Basically a website is what a 'traditional' website remainds you of. It's made with some traditional technologies like HTML/CSS/JS and can use Java or PHP on the back-end.

Web application on the other hand is highly interactive. These sorts of applications can install themselves in the browser to provide some additional advanced functionality. For example (Devdocs.io)[devdocs.io/] can run fully offline. They are not built with traditional HTML (usually), instead they use JS to generate their content.

Basically websites behave like traditional websites, while Web applications behave like traditional software you'd install in your system, with the exception that they run in the browser.

Examples:

• Websites - Dev.to, Wikipedia, BBC.com
• Applications - GMail, Devdocs.io, codeanywhere.com