Availability

The proportion of time or requests for which a service meets its definition of being usable.

An example you can picture

A team counts successful checkout requests rather than assuming an online server means customers can buy. It defines which requests count, which failures matter, and the measurement window.

The distinction that matters

An availability target is only meaningful alongside the indicator and measurement period. A running process may still return errors.

Put it into practice

Choose one task your application serves, such as loading a page or saving a note. Define a successful request and a measurement window. Explain why a server uptime check might miss a failure of that task.

Connect the ideas: slo and metrics. For the bigger picture, read the related learning guide.

Reference

Read the primary documentation for the underlying concept and further detail.