such as the title. Many articles on
about the command free-m have mentioned the difference between cache and buffer, but the word cached is very confusing. At first I thought it was page cache, that was already used, but in fact cached/buffers refers to memory allocated by the system but not used. So which part of page cache is allocated and used? (I don"t know if you understand what I mean by this sentence, cached literally means cached, but actually the explanation is unused)

then the figure is as follows: free-m

         total       used       free     shared    buffers     cached

Mem: 32108 31874 233 0 7 12426
-/ + buffers/cache: 19440 12668
Swap: 0 000

this is a situation in my system. The total memory is 32 gigabytes.

12426 is allocated unused, so the used-cached-buffers in the first line should be equal to the cache assigned and used by the application using the mem+ system. Suppose I have a 16G application running on this machine, then the part of my page cache that is used also accounts for
31874 (os used)-7 (buffer)-12426 (cached)-16384 (app) = 3057

I don"t know if my understanding is correct