Distributions vs. Releases: Why Python Packaging Is Hard

Python has a third: each release has one or more distributions, which are the actual files you download to install a package. In most languages said file is synonymous with the release, but the “or more” is crucial in Python, because for most releases of most widely-used packages, there is in fact more than one distribution. This is because tools like automatically determine the “most suitable” distribution for a release, preferring binary wheels when one is compatible with the given system—and the most specific binary wheel if multiple are—and otherwise falling back to the source distribution.

Source: pydist.com