A food desert, according to healthline's article what are food deserts? all you need to know is an area, normally rural or low income, which holds "communities that have poor access to healthy, affordable foods" it is a prevalent issue in Miami. Below is a video which gives insight into the issue of food deserts, as well as an explanation of how common of an issue it is:
With lack of healthy options being nearby and nutritious food options being scarce, these communities are vulnerable to health issues which are not seen in other communities which may have access to fresh grocers and supermarket chains, such as Publix or Trader Joe's.
Location matters, quite simply- and it has an impact on whether people can access good food options or not, affecting health and leading to inequality.