blueAPACHE — IT Operations Excellence as a Service: MSP & MSSP Glossary

Managed services procurement has a vocabulary problem: the same terms mean different things to different providers, and the differences are exactly where the commercial risk sits.

This glossary defines the terms an evaluator encounters when comparing providers — MSP and MSSP and why the distinction matters, co-managed IT, SOC and SIEM, EDR and MDR and XDR, SLA versus SLO, RPO and RTO, transition-in and disengagement, Essential Eight maturity levels, and the difference between certification, alignment and compliance-aligned.

The last of those is worth flagging before you read further. Certified means an accredited body has audited and issued a certificate against a defined scope. Aligned means controls have been mapped to a framework without third-party certification. Compliance-aligned is weaker still. Providers use all three interchangeably in marketing; only the first is independently verifiable, and asking which one applies is usually the fastest way to test how carefully a provider chooses its words.

Definitions here are written to the industry standard meaning, not to flatter blueAPACHE's own positioning.