Sensitivity, or recall rate, is a statistical measure of how well a binary classification test correctly identifies a condition, whether this be medical screening tests picking up on a disease, or quality control in factories deciding if a new product is good enough to be sold.
The results of the screening test are compared to some absolute (Gold standard); for example, for a medical test to determine if a person has a certain disease, the sensitivity to the disease is the probability that if the person has the disease, the test will be positive.