Maintenance mode is a temporary 'we'll be right back' page WordPress shows visitors while updates or work happen behind the scenes - so people see a tidy notice instead of a half-broken site.
Also known as: Coming soon mode, under construction page
In plain English
When WordPress updates itself, plugins, or themes, it briefly shows visitors a maintenance page instead of the site. The same mechanism is used deliberately to hide a site while work happens - redesigns, migrations, major changes.
Why it matters for your business
Done right, it protects visitors from seeing a broken half-updated site and protects you from the "why is my homepage blank?" panic. Done wrong - or left on too long - it keeps your whole site invisible to customers and search engines.
When you'll run into it
During core updates (automatic, seconds long) and whenever a developer intentionally takes the site offline for work. The danger is forgetting to turn it back off.
A real example
Example: you run a plugin update at 10am and WordPress shows "we are performing a scheduled maintenance" to every visitor while it works - that is maintenance mode working correctly. The problem is when it stays on for hours because an update crashed halfway through.
Run into this on your site?
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