A service level agreement, or SLA, sets measurable service standards between a provider and customer.
Common SLA terms include uptime, availability, support response times, resolution targets, maintenance windows, reporting, service credits and exclusions. SLAs are common in software, hosting, outsourcing and managed service contracts.
A useful SLA should be measurable, realistic and connected to remedies if the service level is not met.
This answer is general information, not legal advice.