Heritability is a measure used in genetics to estimate how much of the variation in a trait within a population can be attributed to genetic differences among individuals. It is expressed as a value between 0 and 1, where 0 means that genetics play no role in the trait's variation, and 1 means that genetics are entirely responsible. For example, traits like height or intelligence can have different heritability estimates based on studies. It's important to note that heritability does not apply to individuals but rather to populations. A high heritability estimate does not mean that a trait is fixed or unchangeable; environmental factors, such as nutrition or education, can also significantly influence traits. Understanding heritability helps researchers in fields like psychology and agriculture to explore the genetic basis of various characteristics.