The process of breaking a code to make information easily understandable is decryption. During World War II, the western Allies used decryption to decode secret messages between Germans that contained military strategy.
While spies have used decryption for generations to decipher coded messages, it's only recently that most decryption occurs on computers. These days, almost all data is encrypted, concealed or protected by being converted to a code. Whether you enter a credit card number to buy something online or simply send an email, your information is encrypted to protect your privacy. Thanks to decryption, your card can be processed and your email can be read by its recipient.