When you buy street foods, you are able to consume them at once. It is the main difference between street foods and restaurant meals. It is possible to say that this ready-to-eat food is a kind of fast food though its price is lower.
Of course, one can argue about its safety and impact on our health. This food belongs to finger food; therefore, there are cases of poisoning and various diseases transmitted by dirty hands, water and products.
A vendor does not have to rent a building and open a restaurant. He is able to sell his cheap food from portable vehicles, for example, a food booth or a food cart. Moreover, a hawker can ride around the city and sell his food in different places every day.