The difference between cache and buffer

1. Cache： Buffer zone , It's cache , It's located in CPU A small but fast memory between memory and main memory , because CPU Is much faster than the speed of main memory ,CPU It takes a long time to read data from memory , and  Cache preserved CPU Just used data or recycled data , Now from Cache It's much faster to read data in , Less CPU Waiting time , Improve the performance of the system .

    Cache It's not about caching files , It's a cache block ( Block is I/O Read and write the smallest unit );Cache It's usually used in I/O On the request , If multiple processes want to access a file , You can read this file into Cache in , So the next process gets CPU Control and access this file directly from Cache Read , Improve system performance .

2. Buffer： buffer , It is used to store data between devices with asynchronous speed or different priority ; adopt buffer It can reduce the waiting time for inter process communication , When a device with high storage speed communicates with a device with low storage speed , For slow data, store it in buffer, To a certain extent, the device with fast storage can read again buffer The data of , In the meantime, store fast devices CPU Can do other things .

Buffer： Usually used to write to disk , for example ： A process requires multiple fields to be read in , When all the required fields are read in, the fields that have been read in will be put into buffer in .