The Affordable Care Act is the blanket term for two laws passed by the federal government in 2010: the Patient Protection and Affordable Care Act (Public Law 111-148) and then an amendment to PPACA, the Health Care and Education Reconciliation Act of 2010 (Public Law 111-152). The function of the Affordable Care Act is to provide access to affordable medical insurance for all American citizens.
The ACA means to accomplish this in two ways. First, the law will expand and improve upon existing Medicaid coverage (which provides medical care for low-income Americans) and existing coverage through the Children's Health Insurance Program (CHIP). Second, the law will establish Health Insurance Exchanges, or online marketplaces where individuals can search available health plans, apply, and be approved for coverage. Some states have established their own exchanges, while other states take part in the nationwide exchange. The exchanges officially opened on October 1, 2013.
The Affordable Care Act is funded through cuts to current government expenditures, a restructuring of Medicaid and Medicare payment systems, and certain taxes and penalties that will be generated upon adoption of ACA.
The act is known informally as "Obamacare," for 44th U.S. President Barack Obama, who was instrumental in the development of the act.