It is generally believed that Seonjeong-jeon and Heejeong-dang respectively served as Pyeonjeon of Chang-deok Palace in the earlier and the later period of Joseon dynasty. However, such belief is based on the concept of Pyeonjeon that emerged after the time of King Soonjo's reign(1800~1834). The concept and functions of Pyeonjeon varied among times ranging from Koryo to late Joseon dynasty. In the earlier Koryo dynasty, the word Pyeonjeon signified both "Pyeonjeon in relation to Jeong-jeon" or "Pyeonjeon as a casual office for the king". The ambiguity of the word was resolved when Bopyung-cheong and Jogye-cheong were established in the earlier Joseon dynasty. These buildings in Chang-deok Palace (and only Bopyung-cheong in Gyeong-bok Palace) held rituals related to events in Jeong-jeon, as well as their exclusive political rituals. Thus, the meaning of the term "Pyeon-jeon" became restricted to its second meaning, namely a casual building for the king's everyday office work and small banquets. However, the ambiguity reemerged from around the time of King Seong-jong's reign(1469~1494). In this period, Pyeonjeon as in relation to Jeong-jeon was often referred to as "Jeong-jeon", or "Beop-jeon" from the mid-16th century. In the 19th century, Pyeonjeon as king's casual office took over the characteristics and functions of Beop-jeon. Thus, the popular notion of "Pyeon-jeon" was newly established and passed onto nowadays.