To establish or found something in some location: We based our organization in the heart of the city.

What is meant by based in?

"Based in" implies the major operations of a business or entity is contained wholly or primarily in that city. "Based out of" implies that though the "home" of the business may be there, the operations of that business take place in other places as well.

What does being based somewhere mean?

From Longman Dictionary of Contemporary Englishbased /beɪst/ adjective 1 [not before noun] if you are based somewhere, that is the place where you work or where your main business is It is a professional service based at our offices in Oxford.