Without a doubt, life insurance is something you need. But it can be a pain to purchase and understand.

A survey last year by the National Association of Insurance Commissioners found that only 28 percent of people with insurance -- life, auto, home, health or disability -- really understood the details of their coverage.

And some types of insurance are more complicated to buy than others. For example, the Consumer Federation of America recently released a report warning consumers about the difficulty in purchasing a type of permanent insurance called variable universal life (VUL).

"Variable universal life insurance policies are so complex that they are difficult for most consumers to purchase intelligently," said James H. Hunt, the consumer federation's life insurance expert and a former Vermont insurance commissioner.

I'll get back to this later, but let me give you a brief overview of the two types of life insurance:

First there is "term" life insurance. With term life, you purchase a set amount of coverage for a specified period of time, after which the premium can be adjusted depending on your health and age. If you miss a payment, the policy may be canceled.

The other type of life insurance is "permanent" life. The biggest selling point of permanent life is the cash value it can accumulate. Permanent policies are known by a variety of names: whole, ordinary, universal, adjustable and variable. If you're thinking about purchasing permanent insurance, such as VUL, here are your basic choices, according to the American Council of Life Insurers:

* Whole life or ordinary life. Whole life policies stretch the cost of insurance out over a longer period to level out the otherwise increasing cost of the premiums. Part of your premium is used to pay for the death benefit, and the rest is invested by the insurance company, which is where the cash value comes from. Eventually you can use some of the cash buildup to pay the insurance premium. You can also borrow against the policy.

* Universal life or adjustable life. This kind of policy allows you, after your initial payment, to pay premiums at any time, subject to certain minimums and maximums. This type of policy usually guarantees a modest interest rate. A portion of each premium payment is used to pay for the insurance, some is used to pay fees, and the rest goes into a cash account. This type of policy is interest-rate sensitive. The cash value grows more in a higher-interest-rate environment.

* Variable life. This type of policy combines a death benefit with a cash value. The premium you pay (again, less certain fees such as commissions and investment-management and administrative charges) is invested. You can allocate your money among a variety of investments (typically mutual funds that invest in stocks, bonds, money-market instruments or some combination of the three). Anyone selling this type of insurance must be registered to sell securities with the Securities and Exchange Commission. The cash value is not guaranteed and grows according to how well your investment choices do.

And then there's the VUL, a hybrid of universal and variable types. Its main attraction is as a tax shelter, the consumer federation's Hunt said. Under current tax law, investment earnings of VULs and other cash-value policies are not taxable if the policy is held until death.

But an array of VUL charges can more than offset the advantage of this insurance product, Hunt warned.

"I think a VUL is the most useful and suitable for professional people, the self-employed, or people making significant incomes who are not eligible for either a 401(k) retirement plan or other tax-deferred plans that reduce their taxable income," Hunt said.

The American Council of Life Insurers took issue with some of Hunt's conclusions, particularly his assertion that buying a VUL policy isn't easy.

"Actually, VULs are quite easy to understand if the individual's goal is to obtain permanent insurance, with premium payment flexibility and choice of accumulation investment vehicle," said William Schreiner, an actuary for the council.

Schreiner said that when buying a VUL, it comes down to asking yourself three questions: Do you want permanent insurance? Do you want flexible premiums? And do you want an investment vehicle attached to that policy? If you answered yes to all three, then a VUL could be right for you.

Whichever type of insurance you choose, here's the most important tip: Don't use the insurance salesperson as your only source of information.

Would you ask only your grocer which foods and how much to buy for your family? I hardly think so. Certainly get advice from your insurance agent, but also do your own research.

There are so many good independent resources on the Internet. If you don't have a computer, go to the nearest public library. Many allow you free Internet access.

One of the best sites I've found is www.insure.com. Another site with good basic information belongs to the Insurance Information Institute (www.iii.org). The American Council of Life Insurers has a brochure called "How to Buy Life Insurance"; you can get it on the Web at www.acli.com/ACLI/Consumer/Default.htm.

Buying life insurance is one of life's big annoyances. It is rocket science. But if purchased correctly, it can be a great benefit to your survivors.

While Michelle Singletary welcomes comments and column ideas, she cannot offer specific personal financial advice. Readers can write to her at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or by e-mail at singletarym@washpost.com.