How to make your own command in cmd?

Question

cmd/bat

Type abc and write aabbcc to the console. Explain to an unknowing person, pls

Answer 1

There are almost no commands in CMD - a lot of things there are executable files.
So what you need is an executable called abc, which will output aabbcc to the standard output, and which will be registered in PATH.
Maybe, of course, aliases were brought into the Windows cmd - then it's easier ...

Answer 2

make the file c:\windws\abc.bat the following content:

@echo off
echo aabbcc