The magnifier icon in the admin header opens admin search: type a few letters to find any admin page - posts, products, orders, settings screens, plugin pages - without navigating menus.
What it searches
- Menu entries - every screen registered in the admin menu, including plugin pages
- Content - jump straight to matching posts/products listings
Results are grouped by area; pressing Enter opens the top result. It searches where things are, not the content inside them - for content search use the listing pages' filters.