Briefly explain what is included in the following provisions which are a part of the Patient Protection and Affordable Care Act (ACA):

-the individual mandate
-the employer mandate
-regulation of private insurers
-state health exchanges

The individual mandate states that every resident of the United States must have health insurance that meets basic requirements or be subject to a tax penalty of $695 or 2.5% of income, whichever is greater.
The employee mandate states that any business with more than 50 full-time employees will be required to provide health insurance to its employees, with the failure to do so resulting in a penalty of up to $3,000 per employee who obtains health insurance from a government health exchange.
The regulation of private insurers provision states that insurers may not deny coverage to anyone because of preexisting medical conditions. Also, insurance premiums can vary based on age, tobacco use, family size, and geography. Premiums may not be raised based on claims history, gender, or overall health status, and lifetime payments for a policyholder are not allowed to be capped.
The state health exchanges provision states that each state will create an online health insurance exchange where the public can purchase health insurance from private insurers. The exchanges are to help customers comparison shop, and should help pool risk and administrative overhead. Low-income individuals are also eligible for tax credits to help pay the cost of health insurance purchased on the exchange.