What does the concept of high availability ensure in Fortinet solutions?

The concept of high availability in Fortinet solutions ensures uninterrupted service and redundancy in network traffic handling. This means that if one component or device fails, there are redundant systems in place that take over seamlessly, ensuring continuous operation without disruption. High availability is crucial for maintaining network reliability, particularly in environments where downtime can lead to significant operational impacts.

In Fortinet's architecture, features like load balancing, failover capabilities, and clustering contribute to this high availability. By utilizing these mechanisms, organizations can ensure that network services remain accessible even in the event of hardware failures or other issues that could disrupt service.

The other options do not fully encapsulate the essence of high availability. For instance, increased bandwidth focuses solely on traffic capacity rather than service continuity, while complete isolation of network segments pertains more to security and traffic management rather than availability. Improved performance of single devices suggests enhancing the capabilities of individual units rather than ensuring that the overall system remains operational in case of failure. Thus, the correct choice emphasizes the importance of redundancy and uninterrupted service in Fortinet solutions.