Raid1 for two WD drives

Hi every1 

Have a good day!

My situation is the following. I’m going to buy two 2tb drives:  2Tb Western Digital My Book Mirror Edition WDH2U20000E

Why not single 4tb drive, you say? Simply cuz here it’s $100 cheaper.

So my question is: will it be possible to set raid1, so that one of those drives will be completely in use (all two terabytes) and second drive will automatically back up all data on first one.

Thanks in advance