Compare two folders which has many files inside contents

Question

Have two folders with approx. 150 java property files.

In a shell script, how to compare both folders to see if there is any new property file in either of them and

Answer 1

To get summary of new/missing files, and which files differ:

diff -arq folder1 folder2

a treats all files as text, r recursively searched subdirectories, q reports 'briefly', only when files differ