Glossary of IT Terms
Plain-language definitions of 30+ data-center, backup, virtualization, and compliance terms.
- RPO (Recovery Point Objective) — the maximum acceptable amount of data loss, measured in time.
- RTO (Recovery Time Objective) — the maximum acceptable time to restore service after an outage.
- Tier (Uptime Institute) — a I–IV rating of data-center redundancy and fault tolerance.
- Concurrent maintainability — the ability to service any component without taking the IT load offline (Tier III).
- N+1 — redundancy where one spare unit backs up N active units.
- vMotion — live migration of a running VM between hosts with no downtime.
- DRS — Distributed Resource Scheduler; automatic workload balancing across a cluster.
- HA / FT — High Availability (auto-restart) and Fault Tolerance (continuous shadow VM).
- HCI — Hyper-Converged Infrastructure; compute and storage collapsed into one software-defined layer.
- SAN / NAS / DAS — block (SAN), file (NAS), and direct-attached (DAS) storage access models.
- RAID — Redundant Array of Independent Disks; trades capacity, speed, and resilience.
- SIEM — Security Information and Event Management; centralised log analytics for threat detection.
- Zero Trust — a security model that authenticates and authorises every request, trusting nothing by default.
- AIOps — the application of machine learning to IT operations telemetry.
- MTTD / MTTR — Mean Time To Detect / Resolve incidents.
- DPDP Act — India's Digital Personal Data Protection Act.
- CERT-In — India's Computer Emergency Response Team, which issues incident-reporting directions.
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