A hybrid SSDD is a regular hard drive, with a small SSD attached. IN this cse, 8GB.
In use, the SSD portion learns what you use the most, and stores that stuff. Use those files, and it is faster. Other files on the drive still run at the same HDD speed.
The fastest storage available is an SSD boot drive. That would be an SSD large enough for Windows and all programs with Windows installed on it. A hybrid solution is meant to mitigate the high cost of SSDs until they drop in price enough to enter the mainstream. This can either be an integrated solution (sold as a hybrid drive in one unit) or as two separate drives used as a hybrid drive. Either way, the basic operation is the same. The bigger HDD is used as the primary storage while a driver (in the case of separate drives) or the HDD controller itself (in the case of an integrated hybrid drive) backs up the most commonly used files on the smaller SSD cache for faster access. The system will take files available on the cache portion first, which speeds up the most common programs and tasks while the rest remain on the HDD.