Hybrid cloud storage is a type of cloud storage model that derives and combines the functionality of public and private cloud storage models to provide storage services. These services are accessed using a Web services API framework or cloud applications.
Hybrid cloud storage is a storage technique that uses internal and external cloud applications, infrastructure and storage systems to form integrated storage architecture.
Techopedia explains Hybrid Cloud Storage
Hybrid cloud storage can be deployed in several ways, but cloud systems are generally designed using in-house storage infrastructure with an external Storage as a Service application. This approach removes the security risk of keeping data in a public cloud storage facility and provides virtualized storage infrastructure through the public SaaS offering, thus providing maximum disk utilization, multitenant architecture and capacity management features.
Another approach in hybrid cloud storage involves building storage applications on top of public cloud storage. For example Dropbox, a cloud storage and backup solution, is built over Amazon S3 and uses a proprietary cloud storage appliance to move data in and out of the Amazon storage buckets.