Electronic discovery, or "e-discovery", refers to discovery in civil litigation which deals with information in electronic format also referred to as Electronically Stored Information "ESI". In this context, electronic form is the representation of information as binary numbers. Electronic information is different from paper information because of its intangible form, volume, transience, and persistence. Also, electronic information is usually accompanied by metadata, which is never present in paper information unless manually coded. Metadata is the data about the data, or the information that is kept about the electronic files ie who the author was, when the file was created etc. It is descriptive information that can not be changed unless spoliation occurs. Electronic discovery poses new challenges and opportunities for attorneys, their clients, technical advisors, and the courts, as electronic information is collected, reviewed and produced.