The patriarchy is a term for a way of organizing society such that men are in aggregate more powerful than women. Feminists analyse many human societies as patriarchal and deem this oppressive of women and others not perceived as male or receiving male privilege.
Some feminists and anti-oppression activists prefer to analyse gendered power relations in terms of kyriarchy and/or intersectionality, finding "patriarchy" too focussed on gendered societal power at the expense of other intersecting oppressions. Others prefer to continue using the term when discussing gendered oppression.