Stores are virtual locations that contain all data corresponding to a real store. A store would contain information like location, timings, and menu. On any aggregator platform, you can see stores of multiple brands based on your location.
Here's a list of multiple outlets of Pizza Hut displaying info. about each outlet.
The same store can be listed on multiple aggregator platforms. Information configured at a store level would apply to all platforms corresponding to the store. A store listed on each platform would be considered a unit.
For example, let's consider a brand: Pasta House and store: RT Nagar. Suppose this outlet is listed on Swiggy & Zomato, the store would be considered as having 2 units.