How to install Ubuntu Server 18 04 LTS on VirtualBox | Ubuntu Server 18 04 LTS install on VirtualBox

Ubuntu is a free and open-source Linux distribution based on Debian. Ubuntu is officially released in three editions: Desktop, Server, and Core (for IoT devices and robots). Ubuntu is a popular operating system for cloud computing, with support for OpenStack.

Ubuntu is released every six months, with long-term support (LTS) releases every two years. The latest release is 18.10 ("Cosmic Cuttlefish"), and the most recent long-term support release is 18.04 LTS ("Bionic Beaver"), which is supported until 2028.

Ubuntu is developed by Canonical and the community under a meritocratic governance model. Canonical provides security updates and support for each Ubuntu release, starting from the release date and until the release reaches its designated end-of-life (EOL) date. Canonical generates revenue through the sale of premium services related to Ubuntu.

Ubuntu is named after the African philosophy of ubuntu, which Canonical translates as "humanity to others" or "I am what I am because of who we all are".

Ubuntu has a server edition that uses the same APT repositories as the Ubuntu Desktop Edition. The differences between them are the absence of an X Window environment in a default installation of the server edition (although one can easily be installed, including Unity, GNOME, KDE or Xfce), and some alterations to the installation process. The server edition uses a screen-mode, character-based interface for the installation, instead of a graphical installation process. This enables installation on machines with a serial or "dumb terminal" interface without graphics support.

Since version 10.10, the server edition (like the desktop version) supports hardware virtualization and can be run in a virtual machine, either inside a host operating system or in a hypervisor, such as VMware ESXi, Oracle, Citrix XenServer, Microsoft Hyper-V, QEMU, a Kernel-based Virtual Machine, or any other IBM PC compatible emulator or virtualizer. Ubuntu 7.10 and later turn on the AppArmor security module for the Linux kernel by default on key software packages, and the firewall is extended to common services used by the operating system.

Has minimum requirements of: 512 MB RAM, 1 GHz CPU, and 1 GB disk space (1.75 GB for all features to be installed).
Runs on all major architectures – x86, x86-64, ARM v7, ARM64, POWER8 and IBM System z mainframes via LinuxONE. SPARC is no longer commercially supported.
Supports ZFS, a file system with snapshot capabilities, since Ubuntu 16.04 LTS.
Has LXD, a hypervisor to manage LXC Linux containers.
Includes the first production release of DPDK for line-speed kernel networking.
Uses Linux 4.4 kernel and systemd service manager.
Is certified as a guest on AWS, Microsoft Azure, Joyent, IBM and HP Cloud.

It has up-to-date versions of key server software pre-installed, including: Tomcat (v8), PostgreSQL (v9.5), Docker v(1.10), Puppet (v3.8.5), Qemu (v2.5), Libvirt (v1.3.1), LXC (v2.0), and MySQL (v5.6).