On writing, > py --version result is "No installed python found!" But When I write >python --version then it would display the python version. Why?

On writing, py --version result is "No installed python found!" But when I write python --version then it would display the Python version. Why does the result differ AND WHY doesn't it display Python version with py --version?

Why doesn't it display Python version when I write py --version andwhy does it say "No installed python found!"

It only displays Python version on writing py --version.