Anyone who has eaten on the streets in Penang, Singapore, Mexico City, Istanbul, Copenhagen or Naples knows about street food. Sometimes it is poor people selling to poor people - that's certainly how it began long ago. Street food then was the only alternative to home food. But it was also the early version of a restaurant - when restaurants didn't exist but people still needed to be fed. In the eastern and southern Mediterranean, for example, travelers stopped for the night in inns that didn't serve food - and their dinners came from cafes, tapas bars, fry shops and panini bars on the streets near-by.

Throughout the world food is served in the streets - baguette sandwiches in Paris, piadine stands in Emilia Romana, kebobs in Turkey, soups in Hanoi, herring in northern Europe, hot dogs in the United States, empanadas all over Latin America. The world of street food is rich and exciting; one-pot meals, slices of fruit, fried dough, little stuffed breads, sandwiches, chestnuts, drinks - prepared and cooked right in front of you and then consumed seated, standing or walking while you take in the sights, sounds and smells of the city.

There are those who say food tastes better on the street. That may or may not be so, but there are a few characteristics that are definitely true of street food:

• It offers variety and diversity of ingredients
• It uses seasonal and local ingredients as well as a variety of cooking
• methods; baking, steaming, boiling, grilling, frying
• It can be found at the heart of cities everywhere, near transportation hubs, office buildings, souks, markets and public squares
• A street food cart or stall is usually operated by an individual or family
• "Marketing" is word-of-mouth or a tourist looking for the stand with the most locals.

Lastly, a universal truth about the street food of the world is that it is practically infinite - thus, it gives us an infinite opportunity for discovery, experimentation and surprise.