It's the same thing, but "programmer" is an older term. They needed a new name to make young React.js programmers feel better about themselves, so they invented "developer".
Discussion
I've always thought of "developer" more like a job title and "programmer" more like an activity.
I'm usually programming things that aren't an essential part of the final, shipable product, that the end-user interacts with, so I don't call myself a developer. ORMs and databases and test automation, and stuff. I've only done bug fixes on core, when someone else was sick or on vacation, or something.