Both are large discount stores that sell groceries and are owned by the same Walmart company. The main difference between Walmart Neighbourhood Markets and Walmart Supercenters are products, size, Locations, prices.
Walmart Neighbourhood Markets:
Produce Fresh meat, pharmacy services and household goods.
It is smaller store
You can find in urban areas
The price is higher

Walmart Supercenter:
It is offer large range of general merchandise and food items
It is average
You can find in suburban or rural areas
It offers affordable groceries