What is the core of Linux Operating System ?

The core component which actually communicates with the hardware and takes commmands from the shell is LINUX KERNAL.The Linux kernel is a Unix-like operating system kernel used by a variety of operating systems based on it. Various distros use it like Fedora, debian etcYou may want to check the following for further here   The Linux Kernel API

Kernel part is core of Linux... It talks to hardware, allocates memory, and bunch of other complicated stuff.

The core of linux OS is its kernel.