A Service Level Agreement (SLA) is a contract between a customer and a service provider that specifies the services to be delivered, their quality and performance objectives, and how service quality issues will be addressed. An SLA in the case of Software-as-a-Service (SaaS) describes the features provided by a SaaS vendor's product as well as the customer's duties. SLAs have various advantages, including improved service, communication, and mutual consent. SLAs are classified into three types: customer, internal, and multilayer. A SaaS SLA should contain service agreements and service management, as well as defined obligations and service level measurement.