Cloud computing refers to the delivery of computing services over the internet. There are different deployment models including private clouds that are customized but have high startup costs and scalability is labor intensive; public clouds that have low startup costs but limited scalability and customization; and hybrid clouds that combine features of private and public. Cloud services can provide infrastructure, platforms, or software as a service. While cloud computing provides benefits like flexibility and easy setup, concerns include privacy, compliance with regulations, legal issues, data portability, security, governance, performance, and continuity of operations.