As a consumer, you expect services you access on the internet to be accessible when you want them. As a business customer, you demand reliability for your cloud services to ensure that your organization can continue to operate fully, whether that's internal operations, hosting e-commerce sites, or another public-facing service.
Resiliency, recoverability, and disaster recovery are high priorities in a cloud service provider's infrastructure design, which is why providers typically rely on a blend of highly available infrastructure designs. These architectures can include network load balancing, data replication, redundant hardware, multiple network paths, and data backups. In addition, service providers also publish Service-Level Agreements that outline their commitments and responsibilities in this regard (for more on Microsoft 365's Service Level Agreements, see Chapter 16, Service Life Cycle in Microsoft 365).
https://docs.microsoft.com/en-us/office365/securitycompliance/office-365-data-resiliency-overview.
When looking for cloud services providers, ensure your service providers have committed to providing a level of availability that meets your business requirements.