In C, an array is just contiguous bytes, and you reach an index through math (starting location + (index * size)).
Pretty sure lots of languages still do this to some degree, as your lookup times are effectively zero, though altering the number of elements is way more complex/expensive than in a linked list.
By the way, that's the only reason why C-derived languages use unintuitive zero-based indexing. There's really no other reason to call the first element a[0] instead of a[1].
Pascal, Julia, R, Lua use more natural 1-based, where you call the first element first.
(You should ideally be able to choose any of these options, and others - e.g., 5, 7, -200, 14,771,589,734,598,742,923,574,835, etc. - because they all make exactly as much logical sense as 1 does and any of them is as elegant a choice as 1 is. But if you get no choice, it absolutely has to be 0, because it's the only non-arbitrary option. No other number guarantees to do nothing to the value you add it to!)