Entry in /proc/meminfo

Question

I am now study linux. cat /proc/meminfo produces as following. Please tell me the mean of entry \"Active(file)/Inactive(file)\". I can\'t find the explanation of these entry

Answer 1

Active — The total amount of buffer or page cache memory, in kilobytes, that is in active use. This is memory that has been recently used and is usually not reclaimed for other purposes.

Inactive — The total amount of buffer or page cache memory, in kilobytes, that are free and and available. This is memory that has not been recently used and can be reclaimed for other purposes.

Ref : https://www.centos.org/docs/5/html/5.1/Deployment_Guide/s2-proc-meminfo.html