A fingerprint may refer to any of the following:
1. When referring to computers and security, a fingerprint or digital fingerprint refers to any trace of information left by someone. Often, if someone has gained unauthorized access to a computer or network, an administrator or security agent may look for any digital "fingerprints" left by the attacker. This identifying evidence may include IP addresses, hostname, MAC address, etc.
2. When referring to computer hardware, a fingerprint scanner or fingerprint reader is a hardware device that verifies a user or enters password information by scanning their finger. The picture is an example of a fingerprint scanner by Microsoft. Computers that do not already include a fingerprint scanner can connect devices such as these to their computer USB ports.