What is the difference between the OS (C:) vs DATA (D:) drives on a laptop. Are they for different things? Can D not be used for games and things like C? Why is D so much larger?
In the old days, computer manufacturers didn’t have a way to easily name drives the nice descriptive names that they do now, so they used letters.
* Typically “A” was for floppies.
* Then “B” was for a second floppy, or backups.
* When hard drives became common, “C” became common for hard drives.
* When CDs became common, “D” was used for the type of drive that could read CDs.
Et cetera, et cetera.
By default, Windows will just use the next available letter after “C” for any new drive it sees, but nowadays, you can assign other drive letters if you don’t want to use the defaults.
It’s just two separate drives. The separation can be physical (i.e. The drives are two physically separate drives) or it can be logical (there’s only one actual physical drive, split into two partitions).
If the separation is logical, then it’s entirely up to whoever installed the machine. It’s common to make a smaller partition for the operating systems and some of the installed software, and a larger partition for all the data – documents, pictures, videos and such. That way you can easily delete the entire system partition without touching the data partition (for example if you want to reinstall your operating system from scratch) However this separation isn’t required – it’s also possible to have just one drive with just one partition which holds everything, both the programs and the data.
Nowadays computers often come with two drives – an SSD (solid state drive) and an HDD (hard disk drive). SSDs are faster but smaller and more expensive than HDDs, so you usually have a small SSD for the operating system and programs (which benefit from fast access to the drive) and a large HDD for the data (which doesn’t need to be as fast).
It is just tradition.
If your computer has a C: and a D: drive you usually use a small fast drive for the OS as C: and a larger slower one for the data.
Even if you just have one physical drive, it might make sense to partition it up into a drive for the OS and one for data so that the data drive ending up full due for some reason doesn’t stop the OS from working.