Patch queues have a superset of the features of shelves. In addition to setting aside work in progress, the major difference is that applying a patch creates a changeset, instead of only changing the working directory. Keeping the patches distinct enables other workflows, such as these from the book:
- "Refreshing a patch" iteratively, giving you checkpoints you can roll back to.
- "Stacking and tracking patches", multiple applied patches don't get mixed together.