DVD licence and Internet licence both allow you to install exactly the same software. So the requirements are the same.
X-plane 11 is still being improved. As a consequence, free updates are regularly available, provided you have an Internet connection.
Currently, the latest stable version is 11.11r2
the latest pre-beta version is 11.20 preview 6 (very buggy)
the latest beta version is... coming soon! (buggy)