Infrastructure as a Service (IaaS) provides virtualized computing resources over the internet, including virtualized hardware, storage, and networking components. It offers the infrastructure on which clients can install their operating systems and applications, providing an equivalent to physical hardware environments.
This allows developers and businesses to develop and run their solutions without managing physical servers.
SaaS delivers software applications over the internet, PaaS provides a platform allowing customers to develop, run, and manage applications, and DBaaS offers database services in the cloud.
References:
* CompTIA A+ Core 1 Exam Objectives Section 4.1: Summarize cloud computing concepts.