CoStar Group is a global provider of proprietary information, analytics, and online marketplaces serving both commercial and residential real estate. The firm operates through a diverse portfolio of brands, including CoStar Suite for commercial real estate research, LoopNet for commercial listings, Apartments.com for multifamily rentals, and Homes.com for residential brokerage. It primarily sells high-margin software-as-a-service subscriptions that provide institutional clients with forensic property data and premium advertising visibility. With operations across North America, Europe, and Asia-Pacific, CoStar maintains the industry's most comprehensive centralized real estate database, functioning as a critical information utility for brokers, lenders, and owners worldwide.