Difference between python, python 2, and python 3

Question

what's is Difference between python, python 2, and python 3

how it's work

Answer 1

python 2 is old and stable and no longer supported for development not like python3... but sometimes there is a package that already release which is not yet supported for python 3... so why other python2 coder still use it becoz they are already created in python2... and also there is a function and tools from python2 that is not required to use in python3.

Answer 2

so then which one you prefer to learn