Hi Sydde.
I have always portioned my drives on my PC.
So I have a c:drive and a d:drive.
No, you have two partitions on the same drive. Windows names them C: and D:, because that's fundamentally how Windows is designed, but they are not drives. They are partitions (logical volumes) on the same physical disk drive. If the disk drive malfunctions, then all your partitions (C: and D

fail at once.
You may never encounter the term
volume in Windows, because it always presents them as drive letters, as if they were real physical disk drives. The name of the volume, its
volume label, plays little or no role in the Windows user interface.
Mac OS is the opposite, and has always been so. Physical drives, hence drive letters, have little or no visible role. Volume names of the actual mounted partition are what Mac OS X shows.
If you were interested in the physical drive's driver, it wouldn't be a letter. It would be a device located in the /dev directory, usually with a name starting with 'disk'. As in this command-line:
There will be a logical driver for each partition, too. Its name ends with s and a number.
You're not expected to know or care about drivers (or physical drives) or their pathnames in order to be an everyday user of Mac OS X. Only admins or programmers might care.
I install programmes on c:drive and save all my files on d:drive.
Having drive letters (volumes on a Mac) is extremely helpful.
No, having drive letters isn't inherently helpful. Having multiple partititions available as logical drives is helpful.
I've partitioned my drives for years and years, often into more than two. I have always found this helpful. I have never needed to refer to them by letters, so I can't see how letters are at all helpful.
Are we then saying that if I partition the drive on my MacBook, I wouldn't know where each part is, and what is being stored where?
I find that "hard" to believe?!
If you have always thought of them as drives with letters, it can be difficult to get used to the other way (partitions with names only when mounted).
As already mentioned, you can name your partitions C and D if you prefer.