The Collections page lists your collections twice. At the top, a strip of pills counts them under Currently Active Collections and Archived Collections. Below the search box the same collections appear as cards, under Active and Archived.
An active card carries Archive Collection and View Collection. An archived card carries View Collection alone, with an Archived marker in the corner.
Currently active collections
These are collections that are live and currently being monitored. Any collection without an end date, or one whose monitor period has not yet finished, appears here.
Archived collections
Once a collection's monitor period ends, it moves automatically to the Archived Collections section. Archived collections are no longer actively monitored, but their data is retained so you can refer back to them at any time.
You can also manually archive a collection by clicking the Archive Collection button if you no longer need to monitor it but want to keep its records.
Archiving does not delete a collection or its data. It moves it out of your active view so the Collections page stays uncluttered.
To bring one back, open it and click Restore. While a collection is archived, Manage units and Edit Collection are greyed out, so Restore is the only thing you can do from that page.