A Service Level Agreement (SLA) is a contract between a service provider and its customers that defines the level of service customers can expect from the service provider. The SLA outlines the services to be provided, including agreed-upon levels of availability, performance, features and functions, as well as any service guarantees or warranties. It also clarifies roles and responsibilities, addressing issues such as maintenance, support, data security, and business continuity. By providing detailed documentation of service levels, an SLA helps ensure that both parties understand their roles and obligations in the relationship and provides recourse if one side fails to hold up their end of the deal.