A Service-Level Agreement (SLA) is a contract between a service provider and a customer that specifies the level of services to be provided. It sets out the responsibilities of both parties and outlines the metrics that will be used to determine an acceptable level of performance. By having both parties agree to the same standards, service providers can ensure they are delivering on their promises and customers can have confidence in the reliability of their services. The SLA should cover topics such as response times, availability, uptime, maintenance, reporting, problem resolution, security, and data back-up.