Service Level Agreement
An SLA (service level agreement) is an agreement between provider and client about measurable metrics like uptime, responsiveness, and responsibilities. These metrics are fundamental to [site-reliability-engineering].
The SLA, SLO, and SLI are related concepts though they’re different concepts.
SLA or Service Level Agreement is a contract that the service provider promises customers on service availability, performance, etc. SLO or [service-level-objective] is a goal that service provider wants to reach. SLI or [service-level-indicator] is a measurement the service provider uses for the goal.