This is the 15837th most frequent German word.
öffentlich
"Öffentlich" means "public" in English.
Here, 'öffentlich' is used as an adjective to describe that the library can be accessed generally by the public.
Die Bibliothek ist öffentlich zugänglich.
The library is publicly accessible.
In this sentence, 'öffentlich' serves as an adverb, indicating that he shared his experiences in a manner observable by the public.
Er sprach offen und öffentlich über seine Erfahrungen.
He spoke openly and publicly about his experiences.
In this case, 'öffentlich' is used as an adjective to show that 'interest' belongs to or is associated with the public.