1TB is a terabyte, thats a serial ATA drive. There is also a 32GB (gigabyte) solid state drive (like a large flash drive). The SSD is for the operating system, the 1TB drive can be segmented into smaller partitions or used whole as a single drive letter. Your choice. The SSD will be your C:\ drive.
SSD drives are faster yep, but you need to optimize them and they are not great for certain types of tasks, so do your homework. Since it's from Dell you probably don't need to do anything. The OS will be on the SSD.