This is the 4175th most frequent Chinese word.
喜悦
Joy; delight.
In this case, '喜悦' is used as an attributive adjective to describe '感受' (feeling).
这首歌带给我一种喜悦的感受。
This song brings me a sense of joy.
In this sentence, '喜悦' is a noun describing the feeling expressed through the children's smiles.
孩子们的笑容中充满了喜悦。
The children's smiles were filled with joy.
Here, '喜悦' is a noun representing the emotional state experienced by the person.