The difference between a Service Level Agreement (SLA) and an Operional Level Agreement (OLA) is that:

SLAs are formal, legally enforceable contracts agreed between the IT service provider and the customer, creating binding obligations on both parties. OLAs, by contrast, are internal agreements between organizational units and are typically best-efforts commitments rather than legally enforceable contracts, reflecting the cooperative rather than contractual nature of internal relationships.

While an SLA defines the service to be provided and an OLA covers internal support requirements, this describes their scope rather than the key distinguishing characteristic - the legal enforceability - between the two agreement types.

Service Level Requirements and Service Level Targets are components that can appear within either an SLA or an OLA; they do not define the difference between the two agreement types themselves.

This choice is imprecise because OLAs are agreements with internal support groups and teams, not with internal customers - conflating internal support groups with internal customers misrepresents the ITIL definition of an OLA.