The purpose of the Karpas is, according to some authorities, to arouse the curiosity of the children, prompting them to ask questions, giving us the opportunity of explaining, by reciting the Haggadah, the meaning of the Festival. During the recitation of the Haggadah, discussion of its meaning and its relevance is encouraged as we shall see when we come to the story of the Rabbis in Bnei Brak.

haggadah Section: Karpas
Source: My Journey Through the Haggadah, Yekutiel Atkins