There are several kinds of whisker:

• For a hair, significant for sensing the surroundings, on the face of a mammal, see vibrissae.
• For a hair on a person's face, often called a whisker, see facial hair or beard.
• For a hair-shaped protrusion from a metal's surface, stronger than is normal for bulk samples of that metal, see whisker (metallurgy).
• An old crystal radio receiver would often use a thin wire called a "cat's whisker" as a contact on a crystal of galena to form a diode.

• A security tool used by computer experts to check for vulnerabilities in applications, see WHISKER homepage. This project is no longer in active development. See Nessus for a similar tool.