Red Hat EX200 glossary of users, storage, services, permissions, and administration terms.
Use this glossary when Red Hat Certified System Administrator (EX200) terms start to blur together. The goal is practical recognition, not encyclopedia coverage.
| Term | Exam meaning |
|---|---|
| systemd unit | Service or system resource managed by systemd. |
| LVM | Logical Volume Manager for flexible Linux storage management. |
| fstab | Configuration file for persistent filesystem mounts. |
| SSH hardening | Configuration choices that reduce remote access risk. |
| SELinux | Mandatory access control system used by many Linux distributions. |
| Cron | Time-based job scheduler for recurring commands. |
| Pair | How to separate them |
|---|---|
| Users, permissions, and filesystems vs Networking and services | 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. |
| Concept knowledge vs task readiness | Concept knowledge explains the right action; task readiness means you can perform and verify it under time pressure. |
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.