Backup External Drive containing Raw Files (Lighroom 5.7)

I just have one simple question.... I hope it is simple....

I have a laptop computer with two internal hard drives. I finally filled up the D Drive and have moved all of my 2013 RAW files and all of my already processed files from 2014 to an external WB 4Tb drive.

I figured out how to do that with Lightroom and that was simple enough. I have saved all the 2013 files to a folder called RAW_2013 and one just like it for the files in 2014. I have a 2Tb external drive to backup the Laptop to. I also have a 4Tb to backup the other 4Tb.

My question is, can I simply just copy all the files on the external Data drive and save them to the Backup drive to serve as a backup? Or is there a reason it would be better to use an actual backup program in this case. I I doubt I will change these old files very often, but if I do it will probably just be to crop them differently to print them or something like that. I just would rather copy it the simple way than have to do a restore if I can.

I use a backup program, Carbon Copy Cloner, because it only copies those files that have changed since the last backup, and thus is quicker. But you could simply copy all the files to the backup location.

I just copy everthing, its one less program I have to use or buy.

I use a nifty little free program called FreeFileSync. It works on PCs & Macs & is pretty easy to setup.

I compares two drives & updates the target drive to match the original. Once you've done the first sync the following syncs only write the changes so it takes less time than another full overwrite.

If you like it you can send them a donation; after using it for a year I gave in and sent them some bucks.