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Linux Foundation ICA Glossary: Service Mesh Terms

Linux Foundation ICA glossary of Istio service mesh, traffic, policy, and telemetry terms.

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Use this glossary when Istio Certified Associate (ICA) terms start to blur together. The goal is practical recognition, not encyclopedia coverage.

Core terms

Term Exam meaning
Sidecar Proxy container attached to a workload to handle mesh traffic.
VirtualService Istio resource that defines routing behavior for requests.
DestinationRule Istio resource that defines subsets, load balancing, and traffic policy for destinations.
mTLS Mutual TLS where both sides authenticate and encrypt traffic.
Gateway Istio resource for mesh ingress or egress traffic entry points.
Control plane Components that configure and manage mesh behavior.

Confusion pairs

Pair How to separate them
Traffic management vs Security Ask which layer the scenario is testing, then match the answer to that layer only.
Control vs evidence A control changes behavior; evidence proves behavior or supports investigation.
Managed service vs custom build Managed services win for lower operational effort unless the requirement needs unsupported customization.
Prevention vs detection Prevention blocks or reduces a bad event; detection finds or reports that it happened.

How to study terms

Do not memorize terms in isolation. For each term, write one scenario where it is the best answer, one scenario where it is a distractor, and one signal that proves it worked.

Revised on Sunday, May 10, 2026