The Rosa Parks Act is a law that protects people from being discriminated against based on their race, skin color, national origin, and other characteristics. It is named after Rosa Parks, who famously refused to give up her seat on a bus in Montgomery, Alabama in 1955, which sparked a civil rights movement.
Just like how your parents tell you not to bully or be mean to someone just because they look different or have a different skin color, the Rosa Parks Act tells everyone that it is against the law to treat people unfairly because of their race or other things they cannot control about themselves. This law makes it so that people can feel safe and protected, and have a fair chance to do things like get a job, go to school, and buy things without being treated unfairly.