It is no longer enough to simply ask someone if they are a programmer. Saying a programmer writes programs is like saying a scientist does science. The difference is that botanists don't design nuclear reactors.
Via Reddit [1], “Erik McClure: "Programmer" is an Overgeneralization [2]”
It took me some time to convince my dad that, while I am a programmer, I do not use, nor understand, Microsoft Windows; there is more to programming than just The Redmond Monopolist Operating System [3]. The above article goes into just a few different areas that all fall under “programming.”
Even system administration (the job of keeping computers fed and happy) has disciplines—you have those that run Microsoft Windows (and even there, you have several different flavors of Windows to manage) and those that run Unix (and here you can even specialize even further—Solaris [4], BSD (Berkeley Software Distribution) [5], any number of Linux [6] distributions).
And even if you know how to run Linux, there's a quantitative difference between running a small network (say, less than 100 machines) and something on the scale of Google [7] (100,000 machines? 500,000 machines? A million?).
(If you are curious, I'm clearing out the backlog here … )
[1] http://www.reddit.com/r/programming/comments/pcyjk/programmer_is_an_overgeneral
[2] http://blackhole12.blogspot.com/2012/02/programmers-are-overgeneralized.html
[4] http://en.wikipedia.org/wiki/Solaris_(operating_system)
[5] http://en.wikipedia.org/wiki/Berkeley_Software_Distribution