Kernel

Kernel is the core of the LINUX OS. It performs following functions:-
a) Device Detection:- During booting kernel detects connected devices and checks whether they are connected or not.
b)Device Driver Initialization:- After detecting connected devices kernel loads proper driver of corresponding device.
c) Mount Root File system:- It mounts root filesystem in read only mode.
d) Execute Init:- It loads and executes initial process i.e. 'init'.
e) Manage Security:- It constantly verifies filesystem permission, SELinux contexts and firewall rules.

To know about you kernal information type following command at prompt:-
uname -a (a for all info)
uname -r (r for release)
uname -s (s for kernel name)
uname -v (v for kernel version)
uname -m (m for machine name)
uname -o (o for operating system)
There are more options you can easily explore.