This is the 1195th most frequent Japanese word.
編
"編" (hen) means "compilation," "editing," or "knitting/plaiting."
編 is used here to refer to a chapter, indicating a division of the book.
この本の第三編は物語のクライマックスを含んでいます。
The third chapter of this book contains the climax of the story.
編 used here stems from the verb '編む' meaning to compose, especially related to creating literary works.
彼は詩を編むのが好きです。
He likes composing poems.
編 in this context is used to refer to a season or a section of a series, indicating a storyline division.