id123

id123 is a generic placeholder identifier used in software development and technical documentation to reference a specific object, record, or resource within a system. As an example, it illustrates how components link data without tying to real-world meaning. The exact character set and length of an identifier called id123 can vary by system; it is typically alphanumeric and may include hyphens or underscores.

In practice, id-like values serve as primary keys or surrogate keys in databases, and as resource identifiers in APIs and user interfaces. The key property is immutability—once assigned, the identifier should remain stable to preserve referential integrity. While business keys carry domain meaning, identifiers such as id123 are usually opaque to prevent unintended coupling and to enable internal changes without affecting external references.

Generation methods include auto-incremented integers, universally unique identifiers (UUIDs), sortable random IDs such as ULIDs, or custom schemes. Each approach offers trade-offs between simplicity, uniqueness guarantees, ordering, and readability. id123 as an example is often used to demonstrate how a system uses a stable, unique tag to fetch or manipulate a resource.

Security and privacy considerations include avoiding sequential identifiers in publicly exposed URLs to reduce enumeration risk, and employing proper access controls and proper validation when using identifiers to access resources.

The term id123 is primarily a placeholder in documentation rather than a specific standardized entity; real deployments replace it with actual identifiers defined by the application's data model.