How do processes of identity verification and user access determination differ?

The process of identity verification (authentication) is confirming that the user truly is who they claim to be. This usually occurs through entering a login and password, using tokens, certificates, etc.

Access determination (authorization) is the process of checking which resources and actions are permitted for an already authenticated user. For example, after logging in, the system checks whether the user has permissions to read, modify, or delete certain data.

In other words:

• Authentication answers the question "Who are you?"
• Authorization answers the question "What are you allowed to do?"

Example: a user enters a login and password (authentication), after which the system checks if they have administrator rights to access the control panel.