Saves a set of files for later use on any node/workspace in the same Pipeline run. By default, stashed files are discarded at the end of a pipeline run. Other plugins may change this behavior to preserve stashes for longer. For example, Declarative Pipeline includes a preserveStashes() option to allow stashes from a run to be retained and used if that run is restarted.
Stashes from one Pipeline run are not available in other runs, other Pipelines, or other jobs. If you want to persist artifacts for use outside of a single run, consider using archiveArtifacts instead. Note that the stash and unstash steps are designed for use with small files. For large data transfers, use the External Workspace Manager plugin, or use an external repository manager such as Nexus or Artifactory. This is because stashed files are archived in a compressed TAR, and with large files this demands considerable on-master resources, particularly CPU time. There's not a hard stash size limit, but between 5-100 MB you should probably consider alternatives.