Fail safe Strike : locked when energized - N/O contact.. Removing the power will automatically allow the door to open.

Fail secure Strike : "open'' state when energized - N/C contact.

Electric Bolt For Fully Frameless Glass Door - Lock when energized Fail safe (N/O contact)

Fail Safe Electric Bolt With Magnetic Feature and Timer - Ultra Slim

The new electro-mechanical locking element with built-in magnetic contact is prevented reliably prevent unauthorized access.
Depending on the control an electrically operated locking bolt goes in and out and thus ensures secure access blocking.