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An in-memory database is a type of nonrelational database that relies primarily on memory for data storage, in contrast to databases that store data on disk or SSDs. In-memory databases are designed to attain minimal response time by eliminating the need to access disks. [Source: Amazon]

is a type of nonrelational database that relies primarily on memory for data

Cloud storage is a service model in which data is transmitted and stored on remote storage systems, where it is maintained, managed, backed up and made available to users over a network (typically the internet). [Source: TechTarget]

, in contrast to databases that store data on disk or SSDs. In-memory databases are designed to attain minimal response time by eliminating the need to access disks. [Source: Amazon]