Update and promote
Every publish is two actions. Update builds; Promote publishes. They are separate so that you always get to look at the site before the public does.
This is also why a Confluence edit never reaches the live site on its own.
#Update
Builds the whole site and uploads it to a private staging preview. Progress runs Queued, Preparing, Processing N of M pages, Finalizing, Complete.

The staging address carries a random token, and a new token is minted every deploy, so old preview links stop working.
Staging always ships a disallow-all robots.txt, so search engines never index a preview.
The preview is kept for 90 days, with a warning from 14 days out.
The live address is not touched.
#Promote
Copies every staging file onto production. It confirms first, naming the live address.
Any live file the new build does not contain is deleted.
Sitemaps are rewritten to the live address, or to your custom domain.
The disallow-all robots.txt is replaced with a permissive one.
The CDN cache is cleared.
Promote copies the build you already previewed. It does not rebuild. If you changed Confluence since the Update, promote the old build or run Update again first.
#Keeping track
The Overview panel tells you where you stand: "N pages changed since last deployment", a link to review the changed pages, and either "Preview matches Confluence" or "Preview is N changes behind Confluence".

#A few things worth knowing
A staging preview that expires cannot be promoted. Rebuild with Update.
Deploys are capped at 12 per hour per site and 12 per tenant, and an export counts against that.
Only one deploy can run per site at a time.
#Related
Update builds. Promote publishes. Neither happens by itself.
