Life Expectancy (at birth) is the average number of years a person living in a particular area would expect to live based on modern mortality rates in that area.

Life Expectancy gap is the difference in the life expectancy figures comparing  gender (difference between male or female) and different areas (difference between wards or local authorities).

Healthy Life Expectancy (at birth) is the average number of years a person would expect to live in good health in a particular area based on modern mortality rates in that area and prevalence of self-reported good health.

The Slope Index of Inequality (SII) is a measure of the social gradient in life expectancy, i.e. how much life expectancy varies with deprivation. It takes account of health inequalities across the whole range of deprivation within an area and summarises this in a single number. This number represents the range in years of life expectancy across the social gradient from most to least deprived.