Costco is a membership-based warehouse club that offers a wide selection of groceries, electronics, household goods, and more at competitive prices. It operates on a bulk-purchase model, allowing members to buy products in larger quantities, which can lead to significant savings. The company is known for its high-quality private label products under the Kirkland Signature brand, along with a range of services such as travel and insurance. With a focus on customer satisfaction, Costco provides a no-questions-asked return policy on most items. The website showcases current promotions and allows members to shop online for home delivery or in-store pickup.