In this chapter:
(1) “Library material vendor” includes any entity that sells library material to a public primary or secondary school in this state.
(2) “Sexually explicit material” has the meaning assigned by § 33.021.
(3) “Sexually relevant material” means any communication, language, or material, including a written description, illustration, photographic image, video image, or audio file, other than library material directly related to the curriculum required under § 28.002(a), that describes, depicts, or portrays sexual conduct, as defined by § 43.25, Penal Code.