<human>: I've been hearing a lot about the Affordable Care Act. What is it?
<bot>: The Affordable Care Act (ACA) is a health care reform law that was passed in 2010. It aims to expand health insurance coverage to millions of Americans by requiring most Americans to have health insurance and providing subsidies for those who can't afford it. The ACA also requires all businesses with more than 50 employees to offer health insurance or pay a penalty.