Cisgender, or cis, describes a person whose gender identity matches the sex they were assigned at birth.
Cisgender, often shortened to cis, refers to someone whose gender matches the sex recorded at birth. A person assigned female at birth who identifies as a woman is cisgender.
The word exists to name something that often goes unlabeled. Without it, being non transgender gets treated as the default rather than as one experience among several.
Cis comes from Latin, meaning on the same side, while trans means across. The pairing simply describes whether your identity sits with or apart from your assigned sex.
In dating, the term shows up on profiles and in conversations about identity, helping people describe themselves and what they are looking for clearly.
Using the word is not political. It is just accurate language that lets people talk about gender without assuming everyone shares the same experience.