Availability is the security concern that is best addressed by moving systems to the cloud. Availability refers to the ability of a system or service to be accessible and functional when needed by authorized users. Availability is one of the key benefits of cloud computing, as it provides high reliability, scalability, and performance for the cloud systems and services. Cloud providers use various techniques and technologies to ensure availability, such as:

Redundancy: Cloud providers replicate the data and resources across multiple locations, such as regions, zones, or data centers, to prevent single points of failure and provide backup and failover capabilities in case of disasters or disruptions.

Load balancing: Cloud providers distribute the workload and traffic among multiple servers or instances to optimize the resource utilization and performance of the cloud systems and services.

Auto-scaling: Cloud providers automatically adjust the amount of resources allocated to the cloud systems and services based on the demand or usage, to prevent overloading or underutilizing the resources and ensure consistent availability.

Monitoring and recovery: Cloud providers continuously monitor the health and status of the cloud systems and services, and provide alerts and notifications in case of any issues or incidents. Cloud providers also provide tools and methods to recover the cloud systems and services from failures or errors, such as snapshots, backups, or restore points.

Availability is different from other security concerns, such as authentication, confidentiality, or integrity. Authentication is the process of verifying the identity and credentials of a user or system before granting access to the cloud systems and services. Confidentiality is the process of protecting the data and information from unauthorized access or disclosure, such as by using encryption, access control, or data masking. Integrity is the process of ensuring the data and information are accurate, complete, and consistent, and have not been modified or corrupted by unauthorized or malicious parties, such as by using hashing, digital signatures, or checksums. References: Cloud Computing Availability - CompTIA Cloud Essentials+ (CLO-002) Cert Guide, Cloud Security – Amazon Web Services (AWS), Azure infrastructure availability - Azure security | Microsoft Learn, What is Cloud Security? Cloud Security Defined | IBM