1.buffer
To write data to memory, the data memory space on Linux systems generally referred buffer (buffer), for example: written to the buffer memory buffer, i.e. the write buffer.
In order to improve write performance, data or media before writing the final the next level media will merge in a buffer. This will increase the write data persistence delay, because after the first write buffer, before data is written down, but also other subsequent writes to round up or timing of the data written to the permanent storage medium.
2.cache
Data read from the memory, the data stored in the memory system is generally referred to as Linux cache (Cache), for example: Cache read from memory, i.e. the read cache.
Operating system read performance and memory allocation performance (cache) file system, the application uses caching with cache to improve efficiency but also to enhance access. Higher operating expenses operating results will be frequently accessed are saved can be prepared at any time in the cache, rather than always get a read disk data.
Cache everywhere, whether it is computer hardware, operating system, or corporate site clusters and other business systems!