Fallout 4 Settlements/Stores

A variety of player-owned merchant stores can be constructed after developing a settlement through Minutemen quests or by clearing out occupied settlements, and reaching level 2 in the Local Leader perk.

Types
There are a total of six types of stores in the settlement build mode each selling different items. There are three levels of each type, requiring an increasing amount of caps, materials, and perk levels to build, but also having more caps available for purchases, and having a wider selection of goods in stock. Assigning settlers to some types of store will increase settlement happiness and all store types will produce a profit of caps based on population size, subject to a maximum limit. Caps can be collected from the settlement's inventory by accessing the workbench under Misc.

Expert merchants
Special characters can be recruited to a settlement to work at each type of store. Every merchant requires a level 3 store and some of them won't offer their services unless the settlement has a large enough population.