This directory contains old versions of some of the datasets available from openstreetmapdata.com (discontinued, until 2019, no longer a link because that domain now only hosts spam) or https://osmdata.openstreetmap.de/ (current as of 01/2022). If you need the latest datasets, go there instead.
These are here because they may be useful for debugging - i.e. to answer the question "does last months version work?".
For obvious reasons, the license is the same as upstream.