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

WordPress is a free and open source blogging tool and content management system (CMS) powered by PHP and MySQL. It has many features including a plug-in architecture and a template system. wikipedia.org

nginx (pronounced engine-x) is a Web server and a reverse proxy server for HTTP, SMTP, POP3 and IMAP protocols, with a strong focus on high concurrency, performance and low memory usage. 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

Ubuntu is a computer operating system based on the Debian Linux distribution and distributed as free and open source software. It is named after the Southern African philosophy of Ubuntu ("humanity towards others").

Zimbra Collaboration Suite (ZCS) is a groupware email server and web client created by Zimbra, Inc., located in Palo Alto, California, USA. wikipedia.org

Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL), are cryptographic protocols that provide communication security over the Internet. TLS and SSL encrypt the segments of network connections above the Transport Layer, using asymmetric cryptography for key exchange, wikipedia.org

Proxmox Virtual Environment, or Proxmox VE, is an open-source server virtualization environment. 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

The Apache HTTP Server, commonly referred to as Apache, is a web server software notable for playing a key role in the initial growth of the World Wide Web. wikipedia.org

The Parallels Plesk Panel software package is a commercial web hosting automation program. It allows a server administrator to set up new websites, reseller accounts, e-mail accounts, and DNS entries through a web-based interface. wikipedia.org

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

Network security consists of the provisions and policies adopted by the network administrator to prevent and monitor unauthorized access, misuse, modification, or denial of the computer network and network-accessible resources. wikipedia.org