Arch Kernel - Difference between kernel linux, linux-lts, linux-hardened, linux-zen

Linux is a clone of the operating system Unix, written from scratch by Linus Torvalds with assistance from a loosely-knit team of hackers across the Net. It aims towards POSIX and Single UNIX Specification compliance.
On a normal installation you will have the package linux installed and contains your kernel. The kernel will update with the normal updates with the command “update” in the terminal. You see the version and the name in the neofetch parameters.
All information about the kernel can be read on this link : https://wiki.archlinux.org/index.php/Kernel


If you're new to Linux, you don't want to download the kernel, which is just a component in a working Linux system. Instead, you want what is called a distribution of Linux, which is a complete Linux system. There are numerous distributions available for download on the Internet as well as for purchase from various vendors; some are general-purpose, and some are optimized for specific uses. We currently have mirrors of several distributions available at https://mirrors.kernel.org/.

Arch Linux is based on the Linux kernel. There are various alternative Linux kernels available for Arch Linux in addition to the stable Linux kernel

Linux
frequent updates
main version changes all the time
security features
new features
likely to work on latest hardware
ideal for newer hardware

Linux-lts 
less frequent updates
main version is same
security features
no new features
may not work on latest hardware
ideal for older hardware

Linux-hardened
A security-focused Linux kernel applying a set of hardening patches to mitigate kernel and userspace exploits.

Linux-zen
Result of a collaborative effort of kernel hackers to provide the best Linux kernel possible for everyday systems.