Oracle Cloud Infrastructure (OCI) is a cloud computing platform offering compute, storage, database, networking, and analytics services. Core strength: Oracle Database services (Autonomous Database most popular). Targets enterprises needing database expertise, compliance, and sovereign cloud options. Three service categories: Infrastructure-as-a-Service (IaaS, compute/storage), Platform-as-a-Service (PaaS, database), Software-as-a-Service (SaaS, enterprise apps).