Religion

What is the difference between Catholic and Christian? Cause I have zero knowledge of religion and I want to be Catholic (since my family is Catholic but they didn’t baptize me because they wanted me to pick my own religion and we rarely practice it at home because they don’t want to force us or feel like they are forcing us so I know nothing about it) but my boyfriend is Christian I want to know the difference and have a better knowledge towards both religion. I tried to do my own research on it but it’s confusing.