Enables smart card (PC/SC) applications to move to the Web platform. It gives them access to the PC/SC implementation (and card reader drivers) available in the host OS. Administrators can control the availability of this API either: - Globally—using the DefaultSmartCardConnectSetting policy. - Per-application—using the SmartCardConnectAllowedForUrls and SmartCardConnectBlockedForUrls policies.
While there are other APIs that provide the right level of abstraction and security properties for identity on the Web, such as WebAuthn, there are domain-specific functions which can't be captured by such higher-level APIs. A remote access (aka "remote desktop") web app letting the remote machine access the host's card reader as if it were directly connected to it. Enabling PC/SC applications on that remote machine to work without modification, unaware that the card reader is not local. A web-based kiosk could read even simple RFID badges via PC/SC and then display relevant information on a display. It's also not uncommon for such readers to need control commands to put them into the proper state for reading the particular type of card the application supports.
Samples: https://github.com/GoogleChromeLabs/web-smartcard-demo
Explainers: https://github.com/WICG/web-smart-card/blob/main/README.md