The description that best describes centralized identity management is that service providers perform as both the credential and identity provider (IdP). Identity management is a type of process that involves defining, verifying, and managing the identity or the information of the users or the entities that access or use a system or a network, or a service or an application, using various methods, such as credentials, identifiers, or attributes. Identity management can provide various benefits, such as enhancing the security, functionality, or usability of the system or the network, or of the service or the application, and ensuring the compliance or alignment with the standards or regulations. Identity management can be classified into various types, such as centralized, decentralized, or federated. Centralized identity management is a type of identity management that involves using or applying a single or a central authority or entity, such as a server or a database, to control and manage the identity or the information of the users or the entities, and to provide or grant the access or the authorization to the users or the entities, for accessing or using the system or the network, or the service or the application. Centralized identity management can provide various benefits, such as simplicity, consistency, or scalability. Centralized identity management can also include various roles or functions, such as:

Credential provider: The role or the function that involves creating and issuing the credentials, such as passwords, tokens, or certificates, to the users or the entities, for authenticating or verifying the identity or the information of the users or the entities, and for accessing or using the system or the network, or the service or the application.

Identity provider (IdP): The role or the function that involves storing and managing the identifiers, such as usernames, email addresses, or phone numbers, and the attributes, such as names, roles, or preferences, of the users or the entities, and providing or sharing the identifiers and the attributes of the users or the entities, with the system or the network, or with the service or the application, for identifying or recognizing the users or the entities, and for accessing or using the system or the network, or the service or the application.

Service provider: The role or the function that involves offering or delivering the system or the network, or the service or the application, to the users or the entities, and requesting or receiving the credentials, the identifiers, or the attributes of the users or the entities, from the credential provider or the identity provider, for authenticating, authorizing, or personalizing the users or the entities, and for accessing or using the system or the network, or the service or the application.