I appreciate that this is a very basic question but having worked with jhipster for half a year or so, I have not been able to find an answer anywhere, and this question is bugging me. Furthermore, it seems from their usage in various places that I've come across that .jh and .jdl files are used interchangeably.
If they are indeed used interchangeably this begs the question why both suffixes continue to exist in the documentation (and code).
Thank you in advance.
No, there is no difference. Both extensions will work.