What does maintenance mode mean in WordPress?

The WordPress maintenance mode page automatically shows to website visitors when you're updating your site, like when you're updating core files, plugins or themes. The point of the maintenance mode page is to prevent your site from looking like it's broken when it's just undergoing routine updating.

Maintenance mode is often used to perform WordPress updates, including core updates, theme updates, and plugin updates. By enabling maintenance mode, you can ensure that visitors don't encounter any issues or errors while updates are being applied.