Paracanonical texts in Theravada Buddhism are like extra books that tell stories about Buddha and his teachings but are not considered the main texts. Imagine you have a favorite book and someone else writes some more stories about the same character and events. These extra stories are not part of the main book, but they still help you understand and appreciate the character and the world they live in.
In Buddhism, the paracanonical texts help believers understand Buddha and his teachings in a deeper way. These texts include stories about Buddha's past lives, commentaries on the main Buddhist texts, and other teachings that were not included in the original canon.
Think of it like an extended version of a movie, with deleted scenes and behind-the-scenes features that give you a better understanding of the story and characters. These paracanonical texts are not as important as the main Buddhist texts, but they still offer valuable insights and teachings for those who want to deepen their understanding of Buddhism.