When I hear the word, "snack", I think of things you can eat, or snack on. In Japan the word snack has an altogether different meaning. If you were to say, "snack" to a Japanese person, they would think you were talking about the local bar, where you have a chance to get to know everyone's names. In Japan, a snack, or スナック is a night club, or a bar. It is not a Dorito, or a Frito, peanuts or popcorn. A snack bar is a place where you can maintain a personal tab, so you can drink now, and pay later. You can even buy your own personal bottle of whiskey or brandy (although at a much heftier price than buying it yourself), keep it at the bar, and drink from it everytime you go to the bar. Once you buy your bottle though, you are as good as in the club.
Snack - スナック - night club or bar in Japan