Android and Linux

The "kernel" in an operating system is basically the digital interface between the hardware and software, in other words the "heart" of the OS. Android uses the open source Linux kernel, customized for their needs. The most popular OS that's commonly referred to as "Linux" is actually the "GNU" operating system that uses the Linux kernel as well. Point of interest, the Windows WSL 2 (Windows Subsystem for Linux) runs on a custom version of the Linux kernel. Microsoft is a member of the Linux Foundation and also supports the Linux kernel security mailing list (a rather select community). Microsoft submits patches to the Linux kernel as it works to create a complete virtualization stack with Linux and the Microsoft hypervisor.