What is SAML primarily used for?

SAML, or Security Assertion Markup Language, is primarily used for making authorization and authentication data accessible across different systems, especially in Single Sign-On (SSO) scenarios. It enables secure communication between identity providers (IdP) and service providers (SP) by asserting that a user has been authenticated and what permissions they have.

The core function of SAML revolves around the exchange of authentication and authorization data in a secure manner. When a user logs in through an IdP, SAML facilitates the transfer of information to the service provider, effectively allowing the user to access multiple applications without needing to reauthenticate. This interoperability is crucial in environments with multiple services relying on a centralized identity management system, thereby enhancing user experience and security.

The other options relate to different aspects of IT and security but do not capture the primary function of SAML. For example, defining web service functionalities or provisioning software applications addresses entirely different aspects of software and infrastructure management. Handling user inputs in forms is more closely related to front-end development and user interface design than to authentication and authorization processes.