This is the 3028th most frequent Russian word.
закончились
"Ended" or "ran out."
The word "закончились" indicates that the snacks are finished or depleted.
Когда пришли гости, закуски быстро закончились.
When the guests arrived, the snacks quickly ran out.
Here, "закончились" is used to denote the cessation of availability of books.
Мои любимые книги закончились, и теперь мне нужно что-то новое читать.
My favorite books ran out, and now I need something new to read.
"Закончились" in this context refers to the depletion or selling out of the concert tickets.