Answer:
Authentication or authentication1 is the act or process of confirming that something (or someone) is who it claims to be. The part that is identified is called a tester. The party that verifies the identity is called the verifier. It is common for the tester to be a user who wants to access certain resources and the verifier is a system that protects access to those resources and has to verify that the user who accesses is a user who has permissions to access those resources. In order to have authentication it is necessary, as a precondition, the existence of biunivocally identified identities in such a way that their identification is allowed.
Authentication, on the other hand, may be required by a system when someone tries to access it. Every time a person wishes to check their email on a webmail platform, for example, they must enter their username and password. The system then proceeds to user authentication: it analyzes the data entered and checks it against the information available in its database. If the data matches (that is, they are correct), the authentication is completed and the system allows access. Otherwise, reject the request. Authentication, in this way, is a security mechanism.
