BadAsAl :
It used to be that a lot of computers from the factory would have a partition for the Windows OS installation and then another partition for data. I can't remember the reason for this on a non-server computer but modern computers don't usually come with the hard drive partitioned anymore. A lot of times people didn't know about the extra partition or understand what the partition was for and it never got used.
As USAFRet said, there is no reason to partition the SSD. You can install Windows on it and just let the install do all the partitioning work. it will create system partitions and a main partition which will be close to the 250GB capacity.
Way back when drive space was really expensive, partitioning used to be a somewhat good idea.
1 partition for the OS, 1 for games, 1 for other stuff. If you need to reinstall the OS, nothing else is touched.
And applications didn't need a reinstallation after an OS reinstall.
Today, with cheap drive space, that is far better done with 'other drives' and folders.
1 drive for the OS and applications, 1 for games, 1 for photo/video work, etc, etc.
Against partitioning? If you have an 80GB partition, and a 50GB game in it, great. Up until you want to install another game which will take up another 40GB. Oops. So you have 30GB in that partition that you can't really use.
If you had the games just living in their own folders, that is self-adjusting.
And with SSD's, that partitioning is merely a
logical separation, rather than a
physical separation. The drive firmware moves data around as it sees fit. It just shows you, the human, different drive letters. It has nothing to do with where the data actually lives on the SSD cells.