Phở or pho is a Vietnamese soup consisting of broth, rice noodles (bánh phở), herbs, and meat (usually beef) (phở bò), sometimes chicken (phở gà). Pho is a popular street food in Vietnam and served in restaurants around the world   Pho originated in the early 20th century in northern Vietnam, and was popularized throughout the world by refugees after the Vietnam War. Because pho's origins are poorly documented, there is disagreement over the cultural influences that led to its development in Vietnam, as well as the etymology of the name.The Hanoi (northern) and Saigon (southern) styles of pho differ by noodle width, sweetness of broth, and choice of herbs.