Octopus Cloud is the hosted version of Octopus Deploy. It has been publicly available since February 2018.
We designed Octopus Cloud and self-hosted Octopus to provide the same functionality; however, there are some minor differences, for instance, with Octopus Cloud, we're responsible for taking backups, automatically upgrading the service, and maintaining and monitoring the underlying systems. For security reasons some of the configuration and diagnostic functionality has been limited in Octopus Cloud.
Learn more about Octopus Cloud.