Same whole life coverage, different ways to pay for it. The shorter the payment period, the higher each premium.
Single premium whole life: one payment buys a paid-up policy with immediate cash value. Because so much is paid in so fast, it almost always fails the federal 7-pay test and becomes a modified endowment contract (MEC). Surrender charges usually apply in the early years.
Limited pay (for example 10-pay, 20-pay or paid-up at 65): premiums stop after a set number of years or at a set age. Each premium is higher than for ordinary life.
Ordinary (straight, continuous-premium) life: premiums are paid for life, up to maturity. The lowest level annual premium of the level-premium forms, and the most common type.
Modified whole life: a lower premium for the first few years (often 3 to 5), then a higher level premium for life. Total cost is higher than straight life.
The 7-pay test (IRC §7702A) applies to every life policy entered into on or after June 21, 1988: if the total paid in during the first 7 years exceeds what would pay the policy up with 7 level annual premiums, the policy is a MEC.
Initial premium from lowest to highest: modified, ordinary, limited pay, single premium.