Whole of life insurance (WOL) guarantees the payout of a lump sum whenever the policyholder dies, so long as the monthly premiums are maintained.
The difference between whole-of-life insurance and term insurance is that term insurance only runs for a set period. If you die in that time, it pays a tax-free cash lump sum (under current legislation tax year 2017/2018) to your loved ones, but if you live beyond the term, your plan has no cash-in value. You won't get any return on your premiums.
Whole of Life Cover is life cover that lasts for as long as you need it so you can be reassured that no matter what happens in your life, you'll be covered.