I have to thank that show from the Food Network - first, for recommending Duarte's Tavern, where we went two weeks ago for dinner, and second for inspiring the title of this post. In fact, this does relate to science fiction and fantasy, as I will get to below.
When we first went to Duarte's, we tried to decide whether it was a Diner, a Drive-in, or a Dive. Drive-in was easy to exclude, because any restaurant that involves driving in and remaining in the car while receiving food is easy to recognize. However, we did spend a bit of time discussing the difference between a Diner and a Dive, and in the end we decided that alcohol was the key ingredient - to be specific, the presence or absence of a bar. Thus, a Diner would be a place that serves food but has no bar, and a Dive would be a place that serves food and also has a bar.
What I found interesting about this from a cultural standpoint - always the viewpoint from which I try to apply things to fantasy and science fiction - is that we were able to come up with such a systematic relation between different types of food establishments. Of course, this classification excludes certain other types of restaurants. But when you think about it, there are quite a few words for places where one consumes food - many of which have come from different cultures (off the top of my head I think of Restaurant, cafe, and bistro). So when you're designing an alien culture, or a fantasy world, it's good to think through what kinds of places people go to get food.
Inns are very common in medieval-style fantasy - like the Prancing Pony in the Lord of the Rings. I've encountered alien restaurants of various sorts in my reading. But as you're putting a world together it's worth considering how culture influences the way the people eat, and in what contexts.
Conceivably one could have a culture where eating food was a very private activity that should be kept in the home - and in such a culture you might have clandestine eating establishments (much as you can find brothels in ours, for a different kind of private activity).
Possibly you might imagine a culture in which food consumption was a highly competitive activity. Maybe eating establishments would be ranked on a tier structure, and competitions of various types might be used to decide who could go to which tier. Perhaps the greatest delicacies would require some form of combat - either a physical combat, or a combat of words and manners - to determine who got to eat them.
Or to elaborate on the concept behind the Diner/Dive divide, maybe there might be a particular type of dish or drink that might be served in one kind of restaurant but not in another, and this distinction could have social significance. Or possibly some activity like dance, or smoking, might be associated with food consumption in one type of establishment but not in another.
It's something to think about.