It's important to understand some of the most important Spring Security terminologies. Let's look at some of them:

• Principal: Any user, device, or system (application) that would like to interact with your application.
• Authentication: A process by which your application makes sure that the principal is who they claim to be.
• Credentials: When a principal tries to interact with your application, the authentication process kicks in and challenges the principal to pass on some values. One such example is a username/password combination and these values are called credentials. The authentication process validates the principal's passed-in credentials against a data store and replies back with the appropriate result.
• Authorization: After successful authentication, the principal is checked again for actions that it can perform on your application. This process of checking rights for a principal and then granting necessary permissions is called authorization.
• Secured item/resource: The item or resource that is marked as secured and requires the principal (user) to successfully complete both authentication and authorization.
• GrantedAuthority: A Spring Security object (org.springframework.security.core.GrantedAuthority interface) that contains/holds permissions/access-right details of a principal.
• SecurityContext: A Spring Security object that holds a principal's authentication details.