Is there any technical difference between these 2 editions or is it just how they are licenced?
Here you can find a comprehensive comparison :
Please note: the Web edition does come with SQL Profiler and management studio
They're close, but not quite the same. The primary difference is the licensing (as you mention). The other differences are around mirroring (web can only serve as a witness), publishing (web can only subscribe), and performance (web does not come with SQL Profiler).
There are more differences when you get out of the SQL Engine and into SSIS, SSAS, and SSRS.
Full comparison of all editions here