Reverse lookup

Reverse lookup is a procedure of using a value to retrieve a unique key in an associative array.^[1]

Applications of reverse lookup include

• reverse DNS lookup, which provides the domain name associated with a particular IP address,^[2]
• reverse telephone directory, which provides the name of the entity associated with a particular telephone number,^[3]
• reverse image search, which provides similar images to the one provided.

See also

• Inverse function
• Reverse dictionary