Service availability in computing refers to the accessibility and functionality of a service or application over a specified period. It is a critical metric used to measure the reliability and performance of a service, indicating the percentage of time that the service is operational and accessible to users. Service availability is typically expressed as a percentage, such as 99.9% uptime, indicating the expected level of uninterrupted service over a given timeframe. Achieving high service availability involves implementing robust infrastructure, redundancy, fault tolerance mechanisms, and proactive monitoring to minimize downtime and ensure continuous operation. Service providers often establish service level agreements (SLAs) with customers, specifying minimum availability requirements and outlining penalties for failing to meet them. Maximizing service availability is essential for delivering a positive user experience, maintaining customer satisfaction, and meeting business objectives.