Plugin Information
View Pipeline Configuration History on the plugin site for more information.

This Plugin tracks changes in your pipeline configuration on a build basis (including replay builds):
On each completed build built from a pipeline config (including libraries) which differs from the latest history entry, a new history entry is created.

These information are stored:

The Jenkinsfile (or the pipeline script if you're not using pipeline via scm)
Globally shared libraries
Shared Libraries accessible to the folder your pipeline might be included in.

The single configurations are viewable file-by-file with each file being downloadable.

You can also easily compare pipeline changes between two builds with a file-wise or all-in-one side-by-side or line-under-line diff view.
Restoring old configurations however is not possible, since that would require a modification in your Jenkinsfile and/ or library scm.