[Mashiro]

I had recently bought another terabyte drive and wanted C to borrow some space from it, but I was not successful, If you have two partitions on the same hard drive, you are able to merge them into a single partition but not from another hard drive altogether.

You actually can do such things but I wouldn't recommend it and I don't think that the OS partition would be properly able to deal with this.

The technology is simply called HDD spanning. You bascially just add the two physical HDDs together to one logic HDD. It's a Non-RAID drive architecture. Alternative names are SPAN or BIG.

In contrary to a RAID you can span together various different disks with different sizes and technologies. As amazing this might sound... it bears a lot of issues and disadvantages. Hence why I don't recommend it. Honestly, I don't even know a proper use case or someone who would really use it these days. RAID is state of the art nowadays.