Kernel Extension (KEXT) and System Extension allow the apps to run powerful and complex functions on Mac operating system. For example, various USB drivers, DNS proxies, antivirus apps, and data recovery software use Kernel and System extensions to enable support for these features on Mac.
KEXT can dynamically load the code in the macOS kernel, resulting in complex apps functioning properly on Mac devices. Therefore, an error or a bug in the code can affect the kernel, leading to an OS crash. However, System Extensions, such as Stellar Photo Recovery Extension, are installed and managed in a tightly controlled user space in the macOS rather than the kernel. This ensures that any instability or bug in the system extension will not affect the functioning of macOS and its apps.
