Not all transgender people transition. For many reasons, medical, financial, social, professional, and other reasons.

Transgender, as an umbrella term, means you do not identify with the gender assigned to you at birth. You don't need to necessarily be transitioning to be trans. And that's totes mcgoats cool.

Cisgender means that you do identify with the gender assigned to you at birth. So say someone was assigned a girl at birth. And they go by she/her pronouns, and they are completely comfortable being called and refered to as a girl. They would be cis. And that's totes mcgoats cool.

Some people may identify outside the binary of gender or be agender and may not even consider themselves trans. That's totes mcgoats cool.

This is a super simplified definition and model. As every person experiences their gender in their own way and can express it however they choose.