No, it’s really not the same thing. It’s a fairly subtle and somewhat mind-melting concept. Colin Fraser gave a great summary of the topic on the Sequentix forum some years back, I’ll see if I can dig it up.
But the gist is, if you record 1 second of audio at 48000KHz in your DAW, you’ll end up with a file that is 48000 samples and if you drop that file in an editor it will of course be exactly 1 second long. However, this 1-second file does not necessarily represent exactly 1 second of elapsed time in the physical world. It’s only 1 second relative to the timing reference of your system clock, which is all but guaranteed to be running a little fast or a little slow within some margin of error.
The amount of drift you’re reporting does seem a bit on the high end (0.008%, or 80PPM), but it’s not orders of magnitude off from what you would expect out of the clock oscillators in an embedded system like the ER-301. Devices generally have pretty good clocks these days because they’re required to make things like USB work.