In the past, the blurring of the distinction between codes and ciphers was relatively unimportant. In contemporary communications, however, information is frequently both encoded and encrypted so that it is important to understand the difference. A satellite communications link, for example, may encode information in ASCII characters if it is textual, or into some other representation of the data such as a JPEG file for an image. In neither case is confidentiality an issue. It then encrphers the resulting coded data into ciphers by using (for instance) the Data Encryption Standard (DES). Finally, the cipher stream itself is encoded again, using error-correcting codes for transmission from the ground station to the orbiting satellite. These operations are undone, in reverse order, by the intended receiver to recover the original information.
Note the multiple meanings of the word code in this example. Thinking clearly with words having such flexibility is not easy.
Most modern ciphers fall into three main categories: Block ciphers, [Stream ciphers]?, and Asymmetric algorithms.
see also Cryptography, Cryptology