Deployment models refer to the various ways in which cloud services can be made available to users. The main types include public cloud, private cloud, hybrid cloud, and community cloud. A public cloud is owned by third-party providers and offers services over the internet, while a private cloud is dedicated to a single organization, providing more control and security. A hybrid cloud combines both public and private clouds, allowing data and applications to be shared between them. Lastly, a community cloud is shared by several organizations with similar requirements, promoting collaboration while maintaining some level of privacy and security.