:Cisgender (sometimes abbreviated to simply cis) is a term for people whose gender identity matches the sex that they were assigned at birth. For example, a cisgender woman is someone who was assigned female at birth and identifies as a woman. The term cisgender is the opposite of transgender.
Transgender people are those whose gender identity does not match the sex they were assigned at birth. For example, a transgender woman is someone who was assigned male at birth but who identifies as a woman.
The term cisgender is not an identity in and of itself, but rather a description of someone's gender identity. It is important to remember that not all cisgender people are the same. Just as there is a wide range of gender identities among transgender people, there is also a wide range of gender identities among cisgender people.
Cisgender people often take their gender for granted because it is seen as the "normal" or "default" gender. This can be difficult for transgender people, who often have to fight for their right to exist and to be recognized as the gender they know themselves to be.
The term cisgender was coined in the late 1990s by activists who wanted to create a word that would be inclusive of all gender identities, not just transgender identities. The word cisgender comes from the Latin prefix cis-, meaning "on this side of" or "on the same side as."
So, to be cisgender simply means that your gender identity matches the sex you were assigned at birth. It is a description, not an identity.