---
title: Comparison of Unique Identifiers: UUIDs, GUIDs, and OIDs
slug: medhistory-populations/guide/comparison-of-unique-identifiers-uuids-guids-and-oids
docTags: 
createdAt: 2026-06-10T15:15:45.765Z
---

| **Identifier**                       | **Definition**                                                                                 | **Format**                                                                                                                                      | **Example**                          | **Standard(s)**                                          | **Usage**                                                                                                         | **Key Differences**                                                       |
| ------------------------------------ | ---------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------ | -------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------- |
| UUID (Universally Unique Identifier) | A 128-bit number used to uniquely identify information in computer systems.                    | Typically represented as 32 hexadecimal characters, displayed in five groups separated by hyphens (e.g., 123e4567-e89b-12d3-a456-426614174000). | 550e8400-e29b-41d4-a716-446655440000 | Defined by the RFC 4122 standard.                        | Commonly used in databases, distributed systems, and applications where unique identifiers are needed.            | Universally unique, not tied to any specific platform.                    |
| GUID (Globally Unique Identifier)    | Essentially the same as a UUID, but the term GUID is primarily used in Microsoft environments. | Identical to UUIDs, as GUIDs are a specific implementation of UUIDs.                                                                            | 550e8400-e29b-41d4-a716-446655440000 | Also follows the RFC 4122 standard.                      | Widely used in Microsoft technologies, such as Windows, .NET, and COM (Component Object Model).                   | Same as UUID, but specific to Microsoft ecosystems.                       |
| OID (Object Identifier)              | A globally unique identifier used to name objects in a hierarchical namespace.                 | Represented as a series of integers separated by dots (e.g., 1.3.6.1.4.1.343).                                                                  | 1.3.6.1.4.1.1466.115                 | Defined by the ITU-T X.660 and ISO/IEC 9834-1 standards. | Commonly used in network management (SNMP), LDAP, and other systems that require a hierarchical naming structure. | Hierarchical structure, different format, and used in specific protocols. |