Term is good if you only need insurance for awhile. 10, 15, 20 years......... (but, companies make the most money off these plans cause they don't usually pay them out)
Whole life and Universal life are insurance tied to a market investment (or something similar). They run the duration of your whole life, but if you die early on in the insurance you typically dont get the whole amount. It is also a tax shelter, one of the best if you make over 150k a year. You put a majority of your earnings into the universal life policy, where it grows tax free, and you borrow against the value of the policy, and pay no interest if you set it up right, so you earn all your money tax free, and when you die, the policy pays off your loan and the excess goes to whoever you want it to go to, but, unless you make more than 150k, its almost impossible to make it worth while.
Most people are best with term, because its insurance in case something happens to you to support your familiy. 10,15,20 years down the road your situation will have changed and you might need more, less or no insurance.