A very simple, albeit silly example was letting someone randomly pick a reward inside a jar full of candies. The normal assumption was that you would get a random candy, and between the mix of candies you liked, simple chocolates, caramels, advanced artisan candies… and some strange concoctions that looked like dirt mixed with spit, there were certainly better and worse options.
This was 'randomness' as defined as a human. Random within a selection that was determined to be logical.
Randomness in the sense of the universe, using the same example would be… the random choice could turn out to be the gaps in the jar between the candies. Or… perhaps even the empty space between molecules in the candy. If one wanted to be more extreme, it might be the literal electron, which would in turn cause a disastrous explosion, or even tiny bacteria that one's eyes couldn't see…
Perhaps it was even a concept that no one had even heard of or discovered yet!