[Cryptography] What is the difference between a code and a cipher?

[Sandy Harris]

On Wed, Sep 3, 2014 at 11:16 PM, Peter Fairbrother
<zenadsl6186 at zen.co.uk> wrote:

> Old chestnut - is it being intended to be hard to decrypt? Having a variable
> key? Something else?

One explanation is here:
http://en.citizendium.org/wiki/Cryptography#Codes_versus_ciphers