Cloud services provide on-demand access to IT resources and applications over the Internet. There are three layers of cloud services: infrastructure (e.g. servers), platform (tools to build apps), and applications (SaaS). SaaS is growing rapidly among SMBs as it allows outsourcing functionality at lower costs. Infrastructure services provide flexibility but don't address scaling or management costs. Platform services abstract infrastructure, allow scaling, and significantly reduce development and operational costs. Concerns around data governance, availability, and security are impacting adoption, driving growth of private clouds which provide more control. Ultimately, both vendors and customers share accountability for security and data ownership.