Answer 1

Programmer - Write code and understand algorithms. Often work alone and well.

Developer - Are the best generalists, can use lots of different systems and languages and get them to talk to each other. Are true and broad professionals, work with people, and communicate well.

Coders - Can pretty much figure out it. It'll work, but it won't be pretty.

Answer 2

To put it straight,
In the eighties they called you PROGRAMMER ...
(Only a few selected people where using computers and did write Software)

In the late Nineties you made a promotion to DEVELOPER...
(Cause automation reached offices and other work environments, so they needed to make the distinction between a Computer user i.e. Data Processor and a Programmer. )

Since 2010 again a new promotion for the IT World, the CODER ...
(The creation of a Popular name was needed to attract young talent in the IT world and as in the Fasion World, the CODER was created...)

This is the real story of software and hardware programmer ...

Answer 3

There is no difference. If you are the real deal, you're all in one. Meaning you should have all three skills even if it is only one skill, but just defined by using three different synonyms for the same referal. Even this is merely a psychological entity that makes you give someone merely a title conform his or hers ability. Actually you are one...

Answer 4

@Annatoli I was watching some YouTube presentations by professional programmers doing some talks at goto conferences. They pretty much echoed your words, these titles and others are pretty much mere semantics.