Judith Butler
As the author and narrator, Butler's projects a personality central to her arguments. She expresses a desire for change in society's relationship to gender. To her, gender cannot be allowed to be the basis of discrimination because that's such an arbitrary standard. She looks to nature to understand the differences between the two genders, but she concludes that there is none. Those boundaries are so fluid within the animal and plant kingdoms that she cannot believe they are fundamental to the human experience. Although Butler's ideas are radical and were considered so during her lifetime, she did spark a conversation designed to challenge male dominance and the way society views women and their abilities.
Women
This is Butler's perceived primary complaint about the historical treatment of women in society. As she explains, the term "women," although being the plural for "woman," has come to signify something different. The word itself has become a character all its own. Its a derogatory amalgamation of the perceived inferiority of women. She believes that "women" can no longer apply to humanity because the word has become so loaded by historical misuse that it cannot appropriately describe a group of people any longer.
Woman
She is the ambiguous individual. This term refers to a character which both everyone knows and nobody knows at the same time. She is personal and undefinable, as the ambiguity of the word "woman" itself suggests. This character is a real person, as opposed to the derogatory and oppressive term "women."