What is the difference between a MOD file and a DYN file

Installation and Setup
1

Dear professor,
recently I was learning the new Cayne DSGE model, but I came across the Dyn file. Could you please tell me the difference between this file and the MOD file? Is it the same in use as the MOD file?

2

Both endings are allowed by Dynare. There is no difference, but .mod is a lot more common.