Select your primary hard drive. SSD is batter for speed and traditional hard drive has larger storage capacity.
Recommended use SSD as primary plus traditional hard drive for storage.
Solid State Drive (SSD) use flash memory as opposed to spinning platters. SSD read and write data significantly faster than a standard HDD. It runs quiet and cool; consume much less power than traditional hard drives, also more stable because there are no mechanical parts.
Examples of the number of photos, songs, videos and any other files that can be stored on a hard drive:
(Data from www.wdc.com)