Cryptography is the use of mathematical techniques to provide security services, such as confidentiality, data integrity, entity authentication, and data origin authentication. Cryptography also is the art or science concerning the principles, means, and methods for converting plaintext into ciphertext and for restoring encrypted ciphertext to plaintext. This goes hand in hand with the Cryptographic Algorithm and encryption. Cryptography is the technique behind encryption, allowing important information to be kept private between the correct people.
Source: NIST SP 800-130, CNSSI 4009