Bistro was originally conceived as French slang that referred to a little cafe or wine shop. This slang term was co-opted by the French from Russian invaders during the 1814 occupation of Paris.

Essentially, not very much. A bistro is a type of restaurant and is just further defined as smaller and more casual than a fine dining establishment. Often, a bistro is described as more of a neighborhood restaurant with community ties, and a warm, cozy, inviting atmosphere.

A bistro is a small Parisian-style restaurant (~20 - ~30 seats) that serves simple meals, wine and coffee in a casual, modest setting. Nothing pretentious and usually a very relaxed atmosphere.

A bistro or bistrot (/ˈbiːstroʊ/), in its original Parisian form, is a small restaurant serving moderately priced, simple meals in a modest setting. The term has also become used by more pretentious restaurants.