An Income Protection plan is designed to pay out a regular income in the event you are unable to work due to an accident or illness. These types of plans continue to pay out an income as long as you are unable to return to work up until the end date of the policy (typically your normal retirement age).
This type of plan is quite often seen as the foundation of any financial planning as it is likely that other plans will have to be given up if you do not have sufficient income coming into the household.