Match each availability property with its description.

### Why this is right Availability concerns more than whether a system is powered on. Users need usable service, enough capacity, timely responses, and reasonable handling of failures and competing requests. ### The concept **Timeliness** concerns how long a user waits for a response or completed service. **Capacity** is the ability to handle the amount of work users require. **Fault tolerance** is a design property that helps a system keep working or fail in a controlled way when a component breaks. **Fair resource allocation** means the system does not unjustifiably give some requesters priority over others. These properties help make information and services available in usable form. A service can be technically running but still have poor availability if it is too slow, overloaded, or unusable. ### The pairs | Item | Matches | Why | |---|---|---| | Timeliness | A request receives a response in an acceptable period. | A delayed response can make a service unavailable for its intended use. | | Capacity | The system has enough resources to meet service needs. | Insufficient capacity can prevent the system from serving legitimate demand. | | Fault tolerance | The system continues or recovers gracefully when a component fails. | Fault tolerance reduces abrupt service loss when hardware or software fails. | | Fair resource allocation | Some requesters are not improperly favored over others. | Fair allocation helps ensure that one requester does not prevent others from receiving service. | ### Terms - **Availability**: The ability of authorized users to access usable information and services when needed. - **Capacity**: The resources available to handle required service demands. - **Fault tolerance**: The ability to continue operating or fail gracefully when a component fails. ### Remember A service is available when people can use it in time, at the needed scale, and despite expected faults.