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

A.
An SLA is legally binding, an OLA is a best efforts agreement

B.
An SLA defines the service to be provided, an OLA defines internal support needed to
deliver the service

C.
An SLA defines Service Level Requirements, an OLA defines Service Level Targets

D.
An SLA is with an external customer, an OLA is with an internal customer