Data mapping is the process used to identify what personal data you use, on what legal grounds, why you use it, how sensitive it is, how long you may retain it, where you process it and where you collect it. It is essential to identifying and responding to any data protection risks. Data mapping informs the content used in communications with various stakeholders, including data subjects and supervisory authorities. In the event of a personal data breach, it is important to know the location and sensitivity of any data which may be impacted.