"Spotlight", the input field for the files-search n on MacBook or Mac, either by Shortcut or by clicking on the magnifying glass in the upper right-hand corner of the screen. How it works via keyboard shortcuts, read here.
Spotlight search by pressing a combination of call
"Spotlight" click on the Shortcut "cmd" + "space bar". It opens the input field in the top-right and you can enter your search phrase.
Tip: Spotlight searches not just documents and programs, but also the content of, for example, E-Mails, and redirects your search directly to Google. Speed up you can use the Spotlight search with the small but powerful Free Tool "Alfred".