A standard hard rive is mechanical - it has a motor and spinning disks the hold the bits of data. A solid state hard drive is not mechanical - it's a memory chip of sorts because it isn't mechanical, it tends to be more reliable and faster to read/write data. The type of drive had nothing to do with playing a CD - totally separate components. IMHO the solid state hard is definitely better. They tend to be costlier, especially when you get into the larger capacity drives, so a popular option is to have a solid state drive as the main drive that holds the operating system and some programs, and a second mechanical drive that will hold terabytes of data, such as what photographers need.