How to read memory usage with the free command

Using RAM freely is normal for Linux. The kernel uses a large amount of RAM to store data associated with local filesystems, remote filesystems, and disks. When reading or writing data, it tries to retain the data in RAM for faster operation. Linux has two types of caching: buffers and page cache. Cache space is generally available for reuse. When a program needs a large amount of memory, the kernel reclaims cache space for that process. Use free to view RAM usage and remaining capacity, as shown below.

[tum@ezylinux ~]# free -m
                         total         used        free     shared    buffers     cached
Mem:                      3948         3860        89          0        282       1401
-/+ buffers/cache:                     2176       1772

Reading the free command output Total RAM used = 3860 MB Free RAM = 89 MB RAM available for use = 1772 MB RAM used by applications = 2176 MB