NEW YORK ( MainStreet) — As Uncle Sam continues to work the kinks out of the Affordable Care Act health insurance exchanges, more consumers are logging on and checking into their options.

With only a few weeks to go before the March 31 deadline for individuals, 3.8 million consumers have signed up for the exchanges through Feb. 25.

The Affordable Care Act is built on the premise that the more people who sign up (especially healthier, younger Americans), the better the system works.

Time is growing short for people to sign up for insurance through the exchanges, and many may have questions that make them hesitate.

"Individuals are able to sign up for health insurance in the federal and state exchanges — also known as the Health Insurance Marketplace — through March 31, so this is a good time for many people to look at their options and make decisions," says Steve Sell, president of the managed health care provider Health Net's Western Region Health Plan.

To help consumers (especially those previously without health insurance) understand what's at stake and what they need to do to sign on to the best plan possible, Health Net is offering a tutorial of sorts to walk buyers through the process. Here's how Health Net defines key terms new insurance customers may not know about:

Premium: The amount of money that must be paid to your insurance carrier. You and/or your employer usually pay the premium monthly, quarterly or annually.

Deductible: The amount you owe for health care services before your insurance carrier begins to pay. For example, if your deductible is $1,000, your plan won't pay for anything until you've met your $1,000 deductible for covered health care services that are subject to the deductible.

Coinsurance: Your share of the costs of a covered health care service, calculated as a percentage of the allowed amount for the service. You pay coinsurance, plus any deductibles you may owe. For example, if the insurance carrier's allowed amount for an office visit is $100 and you've met your deductible, your coinsurance payment of 20% would be $20. The insurance carrier pays the rest of the allowed amount.

Copayments (or copays): A fixed amount (for example, $15) that you pay for a covered health care service, usually as you get the service.

HealthNet also offers definitions for the different levels of insurance plans consumers will find on health care exchanges (bronze, silver, gold and platinum):

Platinum/Gold: With Platinum and gold plans, consumers pay more of out-of-pocket costs when they get care and usually have higher premiums. If you expect numerous doctor visits and other services, a platinum or gold plan may be your better option.