ubuntu find ram size code example

Example 1: how can I check the memory of computer in ubuntu

$ sudo apt-get update
$ sudo apt install htop
$ htop

Example 2: get ram of ubuntu

free -h

#              total        used        free      shared  buff/cache   available
#Mem:      -->  7.7G  <--   6.2G        157M        503M        1.3G        709M
#Swap:          2.0G        118M        1.9G