Here's let's break it down slowly...
Windows 10 users
Can open the Windows Start menu
And type "bash" [enter]
Which opens a cmd.exe console
Running Ubuntu's /bin/bash
With full access to all of Ubuntu user space
Yes, that means apt, ssh, rsync, find, grep, awk, sed, sort, xargs, md5sum, gpg, curl, wget, apache, mysql, python, perl, ruby, php, gcc, tar, vim, emacs, diff, patch...
And most of the tens of thousands binary packages available in the Ubuntu archives!