---
type: Glossary
title: "SNMP Glossary A–Z: Key Terms Explained"
description: "An A–Z glossary of SNMP terms, each with a clear definition and a link to the page that covers it in full — the site's central linking and entity hub."
resource: "https://snmp-monitoring.info/glossary/"
tags: [glossary]
timestamp: 2026-07-11T00:00:00Z
---

# SNMP Glossary A–Z: Key Terms Explained

An A–Z glossary of SNMP terms, each with a clear definition and a link to the page that covers it in full — the site's central linking and entity hub.

## Related concepts

- Up: [SNMP Monitoring Explained — Protocol, Sensors & Tools](/index.md)

## Frequently asked questions

### What does SNMP stand for?

SNMP stands for Simple Network Management Protocol. It's an application-layer protocol, running over UDP, that lets a manager read and sometimes write values on network devices and servers. "Simple" describes the protocol's design; note it doesn't imply security — v1 and v2c are simple but insecure, while v3 adds authentication and encryption.

### What's the difference between an OID and a MIB?

An OID (Object Identifier) is the dotted-number address of a single managed value, like 1.3.6.1.2.1.1.3.0 for system uptime. A MIB (Management Information Base) is the schema that defines those objects — mapping each OID to a readable name, a data type, and a description. In short: the OID is the address, the MIB is the dictionary that tells you what lives at that address.

### What's the difference between a trap and an inform?

Both are notifications a device pushes to the manager when an event occurs, but a trap is unacknowledged — the device sends it and doesn't know if it arrived — while an inform is acknowledged, with the receiver confirming delivery back to the sender. Informs are more reliable over lossy paths at the cost of an extra round trip; traps are lighter but can be lost silently.

### What are USM and VACM?

They're the two security models in SNMPv3. USM, the User-based Security Model (RFC 3414), handles authentication and privacy (encryption) on a per-user basis — it's what makes v3 secure. VACM, the View-based Access Control Model (RFC 3415), controls which OIDs a given user or community is allowed to access, letting you restrict a credential to just the subtrees it needs. USM is the "who are you," VACM the "what may you see."

## Source

Concept generated from https://snmp-monitoring.info/glossary/ — the SNMP Monitoring vendor-neutral knowledge base. Content is limited to what that page states (no external claims added here).