What is, or rather, who is the Media Officer?

A journalist who works for a certain company or civil society organization taking care of external communication? A PR expert who makes sure the organization gets a positive image and support from the outside? A web editor who produces and distributes online materials? An expert in lobbying and advocacy? A communication expert? Probably all of the above and much more, and before delving into different chapters concerning the competences of media officers, let us have a common understanding of this job position. 

For that purpose, I downloaded from the internet a typical vacancy and job description of a media officer: 

The Media Officer produces on- and off-line news and features content across a variety of media. S/he also provides communications advice, capacity building and support to the Network with a specific focus.