The action of coding is to write programming statements for a program.
The action of coding is to write programming statements, or in other words, write the source code for a program.
In communications as well as information processing, code is a system of rules that converts information into another form, which is shortened or secret. This is essentially the process that revolves around encoding, which converts information from a source into symbols for communication or storage. On the other end of this spectrum, we have decoding, which is the reverse process that converts code symbols back into a form that we understand.
In cryptography specifically, code has both specific technical meanings and general meanings. If we look at it from a technical viewpoint, code is the substation of one word or phrase by another word, number or symbol. This is done to conceal the original word or phrase.