Questions for UEFI Secure-Boot, Secure-Boot Key Signing and Management
UEFI secure boot is a protocol of UEFI. Secure boot ensures that the kernel and bootloader you are booting with are trusted and safe. It prevents execution of malicious code during boot.
Nowadays most of the new hardware has support for Secure Boot. Secure Boot can be enabled/disabled using UEFI setting during boot-up.
NOTE: Don't mix Secure Boot with UEFI. Secure Boot is a feature of UEFI but vice-versa is not true.