A portable object or device that counsel uses to store electronic data, such as CDs, DVDs, external hard drives, and flash drives. In e-discovery, when counsel collects electronically stored information (ESI) in response to a request for the production of documents or a subpoena, they typically copy the ESI from its original sources onto media. From the media, counsel can transfer the ESI to another location, such as an electronic discovery vendor, a document review platform, or an attorney's desktop computer, for review before it is produced in a case.

Counsel also may use media to store ESI that they receive from other parties and non-parties.