A good question "What is an SSD hard drive" - here a good answer!
SSD stands for Solid-State-Drive (English) the standard hard disk is called HD (Hard Disk).
The SSD disks does not use conventional magnetic and mechanical components like a standard hard disk, but the solid-state memory, similar to the PC memory (RAM) on your PC, only slightly cheaper and slower!
But much faster than the standard SATA / IDE hard drive. The advantage is that they are much more robust, for example, when they fall down, they do not break so fast and in mobile use, these prove to be very useful.
The power consumption I also much lower, ~ 10 to 20 times less than normal hard drives. Thus, very well suited to improve the battery life on the notebook or laptop. Especially with accesses to the virtual memory.
The SSD Disk
Today will be at the SSD Hard Drives DDR 2.0 NAND flash memory is used and as a cache memory the DDR2 SDRAM memory.
The SSHD Hard Drive
If a conventional HD is combined with an SSD, it is a hybrid hard drive, ie a solid state hybrid disk, ie SSHD .