A policy has disparate impact if it is not intentionally or directly discriminatory, but it disproportionately harms a protected group. A random example might be to require that all employees are at least 6 feet tall. That isn't inherently discriminatory against a protected class so it might appear legal at first look. However it results in disparate impact because women are much less likely to satisfy the requirement than men. It could therefore be ruled discriminatory if the business could not prove why the height requirement was a necessity for the job.