Whats the difference between a personal website and a informational website?

There is no real "difference". Web site is a more anachronistic term that exists from the early days of the internet where the notion of a dynamic application that can respond to user input was much more limited and much less common. Commercial websites started out largely as interactive brochures (with the notable exception of hotel/airline reservation sites).

Over time their functionality (and the supporting technologies) became more and more responsive and the line between an application that you install on your computer and one that exists in the cloud became more and more blurred. If you're just looking to express yourself clearly when speaking about what you're building, I would continue to describe something that is an interactive brochure or business card as a "web site" and something that actually *does something that feels more like an application as a web app. The most basic distinction would be if a website has a supporting database that stores user data and modifies what the user sees based on some user specified criteria, then it's probably an app of some sort (although I would be reluctant to describe Amazon.com as a web app, even though it has a lot of very user-specific functionality).

If, on the other hand, it is mostly static . Html files that link to one another, I would call that a web site.