CentOS is a free operating system distribution based upon the Linux kernel. It is derived entirely from the Red Hat Enterprise Linux (RHEL) distribution. wikipedia.org

A network administrator, network analyst or network engineer is a person responsible for the maintenance of computer hardware and software that comprises a computer network. This normally includes deploying, configuring, maintaining and monitoring active network equipment. wikipedia.org

The Apache HTTP Server is the world's most used web server software. wikipedia.org

cPanel is a Linux based web hosting control panel that provides a graphical interface and automation tools designed to simplify the process of hosting a web site. wikipedia.org

Microsoft Visio, formerly known as Microsoft Office Visio, is a commercial diagramming program for Microsoft Windows that uses vector graphics to create diagrams. wikipedia.org

Active Directory (AD) is a directory service created by Microsoft for Windows domain networks. wikipedia.org

Linux-based operating system known as MikroTik RouterOS. Installed on the company's proprietary hardware (RouterBOARD), or on standard x86-based computers, it turns the computer into a network router and implements various additional features, such as firewalling, virtual private network (VPN) service and client, bandwidth shaping and quality of service, wireless access point functions and other commonly used features when interconnecting networks. wikipedia.org

Microsoft Hyper-V is a hypervisor-based virtualization system for x86-64 systems. wikipedia.org

MySQL is a relational database management system (RDBMS) that runs as a server providing multi-user access to a number of databases. wikipedia.org

Internet Information Services (IIS) _ formerly called Internet Information Server _ is a web server application and set of feature extension modules created by Microsoft for use with Microsoft Windows. wikipedia.org

RAID (redundant array of independent disks, originally redundant array of inexpensive disks) is a storage technology that combines multiple disk drive components into a logical unit. wikipedia.org

Windows Server is a brand name for a group of server operating systems released by Microsoft. wikipedia.org

A system administrator, or sysadmin, is a person who is responsible for the upkeep, configuration, and reliable operation of computer systems; especially multi-user computers, such as servers. wikipedia.org