Highly recommend that you store all user databases, user database logs, and backups on a drive separate from the system drive. So in other words, if your SQL Server is installed on the C drive of a computer, you should be putting all of your data files on a separate drive, and the reason being is because your database files can actually end up being set to grow with no upper limit, and if a database file grows too large and takes up all of the remaining space on your system drive, then your system will actually halt, and Windows can no longer function because it has no more hard drive space left for the memory swap file.
If you are planning to store files in your database, then choose to enable FileStream, and you can do that for TransX SQL access, and for file I O access. FileStream allows SQL Server to integrate with the Windows and TFS file system, and it does so by storing varbinary max data types and the binary large object data types on the file system, rather than in the database itself.
By default, the data and transaction logs are put on the same drive and path. This is done to handle single-disk systems. However, this may not be optimal for production environments. We recommend that you put data and log files on separate disks.
SQL Server data and log files can be put on either FAT or NTFS file systems. On Windows systems, we recommend using the NTFS file system because the security aspects of NTFS.