Great question! There is definitely some overlap between the two.
When we say an internship at Planet Argon, we define that as a fixed period of time (i.e., 1-3 months) where you'll get experience working on projects...whereas we'd consider an apprenticeship as a longer-term period (i.e., perhaps a year?) and is always paid. (and I think that an apprenticeship would be closer to us hiring them as a jr. developer)
With our internships -- we do both non-paid and paid depending on whether they're trying to earn school credits or not.
Some of our usage of "internship" is due to that being common vocabulary amongst the education world. (also, we prefer having a firm timeline for how long the period will last so that we can open up space for the next group of interns)
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