A policy with a revocable beneficiary allows you to change who is designated to receive the benefits of the policy. For example, your spouse could be the beneficiary and if you divorce and remarry, your new spouse could be named.
As long as a policy with a irrevocable beneficiary is in force, the beneficiary can not be changed. Business partners may purchase this type of insurance to minimize the financial impact should one or the other die.
Multiple beneficiaries can be named but it is important to designate the percentage of the death benefit that each receives. For example, if you have three children, you can specify that the proceeds be shared equally or that each gets a predetermined percentage.
Life insurance proceeds can also be specified to pay off mortgages or can go to charities.
The advantage to life insurance proceeds is that they are non-taxable. If your beneficiaries die before you do and you don't designate designate new beneficiaries, the proceeds become part of the estate and are then taxable income to those who inherit your estate.