Phở or pho is a Vietnamese noodle soup consisting of broth, rice noodles called bánh phở, a few herbs, and meat, primarily made with either beef or chicken. Pho is a popular street food in Vietnam and the specialty of a number of restaurant chains around the world. Pho originated in the early 20th century in northern Vietnam, and was popularized throughout the rest of the world by refugees after the Vietnam War.

Source: https://en.wikipedia.org/wiki/Pho