free

free

total        used        free      shared  buff/cache   available
Mem:        4046184     2256816      153752       59596     1635616     1380320
Swap:       4194300     1377564     2816736

-h

free -h

              total        used        free      shared  buff/cache   available
Mem:           3.9G        2.2G        138M         58M        1.6G        1.3G
Swap:          4.0G        1.3G        2.7G

-l

free -lh

              total        used        free      shared  buff/cache   available
Mem:           3.9G        2.2G        105M         58M        1.6G        1.3G
Low:           3.9G        3.8G        105M
High:            0B          0B          0B
Swap:          4.0G        1.3G        2.7G