I did some recent learnings on this too! So, some other terms for you to look up on (**I could be wrong on these definitions, they are all very deep & confusing):

• Essentialism; you must possess some specific feature to be considered a Woman (e.g. XX chromosome). Rebuttal: Did Gender not exist prior to our ability to detect Chromosomes in the 1900s?
• Biological Reductivism (most Conservatives), you must be able to give birth to be considered a Woman. Rebuttal: What about the infertile? What about people who do not give birth?
• Structuralism (1st, 2nd wave Feminism), your status/relationships in society (the structure) identifies your gender (are you oppressed by the patriarchy?), or a more concrete example: A Mother is a mother to a child because of their relation to the child; stay at home and take care of, have authority over the child, and not because they gave birth to the child (biological reductivism). Structuralism is a modernity era school of thought and lends its way to 'gender as a social construct'
• Anti/Non-essentialism (probably most people), a cluster of features, none of which are individually essential, but instead together define womanhood in a fuzzy way (math word). E.g. dress a certain way, look a certain way, talk a certain way. Some may say that these loose cluster of features are just a symptom of Womanhood, and not the true cause of Womanhood (they might say those features come about from social structures)
• Post-structuralism (more 'radical' Liberal), gender is fluid/doesn't matter, a movement away from binary determinations of gender. Why would gender even matter in a world of perfect equality and liberated sexuality?