Restaurant is the general word for any business serving meals. A bistro is a particular kind — small, informal, traditionally French, with a short menu of simple dishes and modest prices. Every bistro is a restaurant; most restaurants are not bistros. The word signals a style, not a standard.
The core difference
One is the category, the other a style within it.
- restaurant — any establishment serving prepared meals to customers.
- bistro — small, casual, short menu, traditionally French and modestly priced.
The related French terms
Brasserie is larger than a bistro, serves all day, and traditionally brewed its own beer — the word literally means brewery. Café centres on drinks with lighter food. Trattoria is the Italian equivalent of a bistro; osteria is simpler still.
A word about the origin story
A popular tale says bistro comes from Russian bystro, "quickly", shouted by soldiers occupying Paris in 1814. It is a good story and almost certainly false — the word is not recorded in French until the 1880s, seventy years later.
