In modular synthesizers, the term "patch" refers to a particular configuration of knobs, faders, patch cable connections, etc. for a single module or an entire rig of modules. The term has generalized to include software synthesizers.
Although many individual synth modules have patch store and recall, a configuration of an entire modular rig is generally ephemeral. This is a bit unfortunate since patches can contain entire works of music. That hasn't stopped people from recording their patches by diagramming them on paper and/or taking photos.