Common Understanding Wiki
A Common Knowledge Source of Terms and Definitions
A software developer writes code in one or more programming languages. In order to do that he may rely on existing libraries.
Operators (administrators) are responsible for running dedicated applications. They are also responsible to apply bug fixes and ensure the integrity of the entire system.
DevOp is a organisational philosophy that targets the possibility of instant delivery of the latest version of a product. It has become increasigly popular in software developement and software operation (which also constitute its primary origin). In that field, DevOp refers to mixed teams responsible for both developing and operating a software system in order to release the Gordian Knot where operation teams would not want to change a stable system in order to not introduce new bugs and problems; and the software developers that would want to push new features to the running system as early as possible.
This has led to the development of several techniques that enable a permanent building of new software features (mainly automated unit test) and the continous integration of these changes to other dependent software components of the same product, but also to external services mainly by using service virtualisation.