Discover what goes into a service-level agreement (SLA), which type of business usees them and why, and how to create your own. An SLA (service level agreement) outlines expectations between a service provider and a customer. Learn how to set SLAs, measure performance and more. A service level agreement (SLA) is a formal contract between a service provider and a client that defines the level of service expected during its term. Explore the components of an SLA, who uses them, and why they are essential for your business. SLA stands for service level agreement, a contract that outlines the level of service a supplier promises to deliver to a customer. Learn about the types, elements, and metrics of SLAs, and how to monitor vendor performance against them.