An electronic health record (EHR) is a digital version of a patient's medical history that is maintained by a healthcare provider. EHRs contain comprehensive medical and treatment histories and allow authorized users to access patient information instantly. While EMRs contain data from a single practice, EHRs include information from multiple providers to present a fuller patient history and enable better care coordination. Meaningful use criteria require that certified EHR systems are used to improve quality, engage patients, and enhance health information exchange.