1. id
Displays the user who executed the program:
root@kali:~# id
uid=0(root) gid=0(root) groups=0(root)
root@kali:~#
2. uname -a
Displays the kernel name, hostname, kernel release, kernel version, machine name, processor (if known), hardware (if known) and operating system.
root@kali:~# uname -a
Linux kali 4.9.0-kali3-686-pae #1 SMP Debian 4.9.18-1kali1 (2017-04-04) i686 GNU/Linux
root@kali:~#
3. lsb_release -a
Displays which version of Kali-Linux is currently installed
root@kali:~# lsb_release -a
No LSB modules are available.
Distributor ID: Kali
Description: Kali GNU/Linux Rolling
Release: kali-rolling
Codename: kali-rolling
root@kali:~#