A cipher is an algorithm used for the encryption and decryption of information. Ciphers are well-defined steps / processes that must be conducted in order to hide / reveal a message. Ciphers have been used for thousands of years before the arrival of computers by militaries and royal families to send messages between one another. If a messenger of a royal family is carrying a message to another kingdom and is robbed along the way, the robbers will not know what the words on the paper say. Traditional ciphering is typically the shifting of letters in some direction by an arbitrary amount.
Example:
word = eat
Cipher = (+1)
cipherword = fbu
The letters used to spell “eat” are substituted by the first letters ahead of them; E-F / A-B / T-U. So to decipher “fbu” the inverse operation of (-1) must take place.
Whenever a message is being encrypted it must be converted into cipher or ciphertext. (Cipher text is a seemingly random combinations of letters and numbers.) With the advent of computational technologies, traditional methods of ciphering have become obsolete and new methods have taken their places. Current methods of ciphering include the use of Hashes or hashing functions.
To cipher something simply means to encode it, therefore to decipher something is to decode it.