LINUX, WHM, CPANEL

Linux is a generic term referring to Unix-like computer operating systems based on the Linux kernel. Their development is one of the most prominent examples of free and open source software collaboration;[citation needed] typically all the underlying source code can be used, freely modified, and redistributed, both commercially and non-commercially, by anyone under licenses such as the GNU GPL.
Linux is predominantly known for its use in servers, although can be installed on a wide variety of computer hardware, ranging from embedded devices, mobile phones and even some watches to mainframes and supercomputers.Linux distributions, installed on both desktop and laptop computers, have become increasingly commonplace in recent years, partly owing to the popular Ubuntu distribution and the emergence of netbooks.
WHM – Cpanel

cPanel is a unix based web hosting control panel that provides a graphical interface and automation tools designed to simplify the process of hosting a web site. cPanel utilizes a 3 tier structure that provides functionality for administrators, resellers, and end-user website owners to control the various aspects of website and server administration through a standard web browser.
In addition to the GUI interface cPanel also has command line and API based access that allows third party software vendors, web hosting organizations, and developers to automate standard system administration processes.