Every countryman uses the words airport and airfield in his speech. Often, citizens substitute one word for another, not unreasonably considering them to be close in meaning and even related. But do the words airport and airport really mean the same thing and don't we all make a mistake by substituting these terms with each other?
In fact, the words airport and airfield mean different, though related, things. The Greek roots used in these words already hint at this. The root "aero" is common to both terms. It only means "air. The root "port" comes not from the Greek word, but from the Latin "portus" and means "harbor. But the root "drom" is Greek and means "street" or "road". So an airport is an air harbor, and an aerodrome is an air road.
An airfield is a place of landing and maintenance.
Therefore, in the narrow sense an airfield is only one part of any modern civil airport. In its broad sense, an airfield usually refers to a military, sport or utility facility, which does not carry passengers on a commercial basis. In this respect, an airport is a much broader term that implies not only runways and technical infrastructure, but also commercial as well as passenger infrastructure.
The main difference between an airport and an aerodrome is that the former is intended specifically for the commercial transport of citizens. It is possible to replace these notions with each other, but from the point of view of the correctness of speech to do so is not too correct, because in Russian there is a well-established and long-established tradition of using both words.