What is a security token in API usage?

A security token serves as a digital representation of a user's identity that enables authentication in API calls. When a user attempts to interact with an API, they often need to prove their identity to gain access to the system or data. A security token is generated as part of this authentication process, typically after the user successfully logs in or verifies their identity through some means (like using a username and password).

When the user sends requests to the API after obtaining the security token, it is included in the request headers or parameters. The API can then verify the token to ensure that the request is coming from an authenticated user. This process is critical for maintaining the security of the API and the data it handles, as it helps prevent unauthorized access.

The other options do not align with the definition of a security token in the context of API usage. A promotional code relates to marketing benefits, a type of database entry does not connect to user identity, and an encryption method refers to securing data rather than authenticating user identity.