What Is Cryptography? Explain

Cryptography is the study and practice of hiding information or converting it into codes. The modern science of computer security, information theory and engineering make use of Cryptography for various applications such as ATM's etc. To find more information on the subject, see the link below:
en.wikipedia.org

Cryptography is what is done to a normal text to give more security. First the original text is changed into a cipher text then back to the original text. In this manner, no one can understand the cipher text, except the sender and receiver. For example there is a word ABCD which means it can be 1234. This order is sent afterwards to the receiver.

The study of codes.