http://www.seagate.com/support/kb/disc/tp/cache.html

Since computers tend to access the disc drive in a sequential or predictably ordered manner, performance can be greatly increased by reading extra data into a memory cache before the computer asks for it. This way, when the computer asks for the next bit of data, it is already in memory, and data retrieval from memory can be several thousand times faster than having to get it from the disc. Tests show that if a computer requests data from a certain location, there is an 80% to 90% chance the next request will be for data in the following location. Unfortunately, using a cache to improve performance is a gamble. We make the effort to read the extra data based on the 80% chance it will be used next.

Caching, in effect, anticipates requests for certain data (usually the next in line) and draws that data into memory before the system needs it. Because the caching program reads information into memory before it is needed, it is often also called a Read Look-Ahead Buffer. Caching occurs at many levels within a company, so it is not necessary for the cache to reside with the host computer's main memory. A disc drive can handle the caching for itself, leaving the host computer free from the burden of managing the cache for that device.

>>>Caching is often also called a Read Look-Ahead Buffer

http://www.seagate.com/support/glos...che_buffer.html

Cache Buffer
A bank of solid-state memory on a drive that stores some data from the discs. The system may then refer to this memory for information instead of going to the media, increasing the processing speed.

Cache Buffer 比較完整的說法