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 Section 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 Section 28.002(a), that describes, depicts, or portrays sexual conduct, as defined by Section 43.25, Penal Code.