Costco is a ‘store’. Very similar to Sam’s Club in how it operates. These sort of businesss used to be called Warehouse stores, but that name has sort of faded. They charge an annual membership fee and try to include everything from electonics to clothing to food to pharmcey in the inventory. They also have auto stuff (tires etc). Pricing is very good for many products, but you have to know the items to make an intelligent comparison. Google Costco.com and you will find a list of 7 PA stores. I don’t know if any are close to you. Before you join, visit a store and do a walk thru…They are a real bargain to some folks, and not much to consider for others. It depends on you individual shopping likes and dislikes. I do find their quality to be much better than SAM’S Club.