Linux - Synchronise 2 Directories

rsync -avu --delete "/home/user/A/" "/home/user/B"

-a

archive mode; equals -rlptgoD (no -H, -A, -X)

-v

run verbosely

-u

only copy files with a newer modification time (or size difference if the times are equal)

--delete

delete the files in target folder that do not exist in the source

Reference: Stack Exchange: How to sync two folders with command line tools?