how to know which os in linux code example

Example 1: find operating system linux

#Get details about linux distro
cat /etc/os-release

Example 2: how to check linux os

cat /etc/os-release
or
hostnamectl

Example 3: how to find distro name

cat /etc/os-release
lsb_release -a
hostnamectl
Type the following command to find Linux kernel version:
uname -r