By The Associated PressHealth insurance exchanges will change the way people buy coverage and will help millions of uninsured people get a private plan. Nearly 49 million people are uninsured in the United States, but the numbers vary dramatically by state. Exchanges will be the most visible part of President Barack Obama's health care overhaul law in everyday life. Open enrollment starts Oct. 1, less than 10 months away. Some questions and answers on how the exchanges will work: Q: What's a health insurance exchange? A: "Exchange" is just another word for "marketplace." The plans sold in the new markets will start covering patients on Jan. 1, 2014. Each state will have its own exchange serving people who buy their health insurance directly, as well as a separate one for small businesses. The vast of majority of people now covered by employer plans will not see a change. There will be three types of exchanges at the beginning: those run by states, those run by the federal government, and partnerships. Most Republican governors opposed to "Obamacare" are letting Washington run the exchanges in their states. For consumers, the benefits should be the same no matter who runs the exchange. Q: How will exchanges work? A: Exchanges are supposed to have the feel of an online travel site â¿¿ think Orbitz or Expedia. Middle-class people will be able to pick from a range of private insurance plans, and most people will be eligible for help from the government to pay their premiums. Low-income people will be steered to safety-net programs for which they might qualify. This could be a problem in states that choose not to expand their Medicaid programs under a separate part of the health care law. In that case, many low-income residents in those states would remain uninsured.