I have a particular folder named 'Photos' where I store all my photographs. I regularly update this folder by copying in new photos from my camera SD card, Phone memory, etc. This is a huge folder ~ 200GBs so far and I would like a way to automatically back up this folder incrementally to an external hard drive.

Basically what I am looking for is that the backup folder in the external drive should be a mirror image of the 'Photos' folder in my laptop, and that any changes in the original folder ('Photos') should sync automatically to the backed up folder. Is there any tool/utility that would enable me to do this?