Source Distributions vs Wheels
pip can install from either Source Distributions (sdist) or Wheels, but if both are present on PyPI, pip will prefer a compatible wheel. You can override pips default behavior by e.g. using its–no-binary` option.
Wheels are a pre-built distribution format that provides faster installation compared to Source Distributions (sdist), especially when a project contains compiled extensions.
If pip does not find a wheel to install, it will locally build a wheel and cache it for future installs, instead of rebuilding the source distribution in the future.