What does Authentication Server mean?
An authentication server is a type of network server that validates and authenticates remote users or IT nodes connecting to an application or service. It ensures that only authorized and authenticated nodes are provided access to the server, application, storage or any other IT resources behind the authentication server.
Techopedia explains Authentication Server
An authentication server is primarily used in enterprise IT environments to secure network/internet based applications and services. Typically, validating the identity and granting access of connecting nodes is the prime objective of an authentication server. These nodes can be general end-user, computer, server or an application.
An authentication server requires each node to provide valid authentication credentials before they are authorized access. Moreover, an authentication server can be a standalone server, firewall application, integrated with a switch or network access server.