Also Jupyter Notebook (pure notebook interface) is evolving into Jupyter Lab (a notebook-oriented IDE). The latter is much more IDE-like than the former, though the former is still really good.

Technology evolves...

Summary: Jupyter is the evolution of IPython. IPython is deprecated.

Jupyter is the language-agnostic parts of IPython (UI, notebook format, protocols to talk to notebooks, ...) extracted out to be used with many languages.

IPython remains as the project maintaining the Python-specific parts of that stack. It's not deprecated, but has been limited in scope.

IPython still makes nicer-repl-for-python. I don't know if it has a name beyond just IPython, which is a bit confusing.