Free Memory on linux

You want to know nemory statistics on a linux box?
If this is the question, one can find various ways. Some if them are
1. free -m or free -g
The free command displays the total amount of free and used memory and swap memory in the system

2. cat /proc/meminfo
Gives you
MemTotal MemFree and so on in KB

3. vmstat -s
vmstat can display memory statistics including additional information about process, paging, cpu activity and so on

4. top command
top command lists the total memory used memory and free memory