What is a software developer?

A non-technical query, hopefully still relevant here.

The description of "software developer", Is this a subsection of the computer sciences or is it a domain of its own?

Is it similar to the description of "mechanical engineer"? Mechanical engineer is a fairly broad term given the many disciplines within the domain of engineering.

Or is sofware developer a sub section of a discipline in the computer sciences?

What does the hierarchy look like?