In Cloud storage there is no need to rack & stak servers and your companies files are stored on external servers typically managed by another company and you have access to these serves and can manage your account remotely, whereas On-Premise storage means your company's server is hosted within your organisations infrastructure and in most cases is physically onsite
Advantages of Cloud storage:
1. Cost & Maintenance
2. Security & threat protection
3. Scalibility
4. Realibility
5. Data Backup
8. Access anywhere (via mobile app. browser, pc)