Definition
High Availability (HA) is an architectural approach to designing systems so that services can continue operating despite the failure of individual components.
Human Explanation
The system is designed so that another component or path can take over when one part fails, limiting interruption to users.
Why it Matters
High Availability reduces avoidable downtime and supports services whose interruption would have significant consequences.
Conceptual Boundary
High Availability does not guarantee uninterrupted operation under every failure and does not remove the need for recovery planning. It is an architectural approach, not the achieved availability result itself.
Practical Perspective
HA commonly depends on redundancy, health monitoring and automated failover, but these mechanisms must avoid shared dependencies that can still cause a complete outage.