Bieszczady is the polish name of the western part of what the poles call eastern beskids (beskidy wschodnie). It is a part of the carpathians. The mountain range is situated between the łupkow pass (640 m) and the vyshkovskyi pass (933 m).
In a narrower but very frequent sense, bieszczady refers only to the western bieszczady or even only to the polish part of the mountain range.
There is a unique national park, the Unesco east carpathians biosphere reserve, split between three countries and comprised of bieszczady national park (poland), poloniny national park (slovakia) + uzhansky national nature park (ukraine).