Chances are good that the date you scheduled, the letter you wrote, and the inter-office message you just read have all been recorded on magnetic media. Like any other business record, electronically stored files are discoverable in litigation and can be used as evidence in the courtroom.

What distinguishes computer-based evidence from traditional paper documents in discovery? "Electronic" documents thought to be lost or destroyed can be recovered. Valuable information such as the time, date, and author's name may be embedded in the electronic version of a document. Comparisons of computer backups to existing documents can be used to show that a critical document was altered and when the event occurred. In the case of electronic mail, casual and candid correspondence may be frozen in time like insects in amber.

Computer System refers to the entire computing environment. This environment may consist of one large computer serving many users (e.g., a mainframe or mini-computer) or one or more personal computers working individually or linked together through a network. A computer system includes all hardware and peripherals used (e.g., terminals, printers, modems, data storage devices), as well as the software.

Files are groups of information collectively placed under a name and stored on a computer. Files are organized in various folders sometimes referred to as directories and subdirectories.

Media is the generic term for the various storage devices used to store computer data. For PCs, the most common media are the internal hard drive, CDs, and floppy disks. Backup tapes, thumb drives, and DVDs are other forms of storage media.

Networks are the hardware and software combinations that connect computers and allow them to share data. Two common ways PCs are networked are peer-to-peer and client-server. Peer-to-peer networks physically connect each computer in the network to every other computer in the network. Files are stored on the hard drives of the individual PCs with no centralized file storage. Client-server networks connect individual PCs called "clients" to a central "server" computer. In contrast to peer-to-peer networks, files are stored centrally on the server.