Buffers and Cached

Buffers and cached are designed to improve data access performance and reduce disk I/O operations

buffers
Buffer size used to make a block device
For example, directory content, permissions

Cached
Used to buffer files.
For example, an open file

Test
To execute the man command two times, you can obviously feel that the second time a lot faster. And observe the change of the free command.

# free
             total       used       free     shared    buffers     cached
Mem:       1027192     854960     172232      32716     100944     261892
# man       socket     Shared    buffers     cached
Mem:       1027192     855476     171716     32716 100948 262272