This is the 17339th most frequent Korean word.
선보이던
"선보이던" translates to "was showcasing" or "was presenting."
In this sentence, '선보이던' is attributing the act of showcasing a technology in the past to 'this technology', emphasizing its historical usage.
과거에 선보이던 이 기술은 이제 매우 흔한 기술이 되었다.
The technology that was showcased in the past is now a very common technology.
Here, '선보이던' is modifying 'gallery', specifying that it used to have an activity of showcasing various works of art.
다양한 예술 작품을 선보이던 갤러리가 최근에 문을 닫았다.
The gallery that showcased various art pieces recently closed.
Here, '선보이던' describes the stage as the one where the showcasing of a new dance style was occurring, functioning as an attributive modifier for 'stage'.