The nature of digital data makes it extremely well-suited to investigation. For one thing, digital data can be electronically searched with ease, whereas paper documents must be scrutinized manually. Furthermore, digital data is difficult or impossible to completely destroy, particularly if it gets into a network. This is because the data appears on multiple hard drives, and because digital files, even if deleted, can be undeleted.

In the process of electronic discovery, data of all types can serve as evidence. This can include text, images, calendar files, databases, spreadsheets, audio files, animation, Web sites, and computer programs. Even malware such as viruses, Trojans, and spyware can be secured and investigated. Electronic mail (e-mail) can be an especially valuable source of evidence in civil or criminal litigation, because people are often less careful in these exchanges than in hard copy correspondence such as written memos and postal letters.

E-discovery is an evolving field that goes far beyond mere technology. It gives rise to multiple legal, constitutional, political, security, and personal privacy issues, many of which have yet to be resolved.