As with the default installer, the alternate installer is downloaded in the form of an ISO image that we can use to create a bootable CD/DVD or flash drive. To download the alternate installer, visit the following website: http://cdimage.ubuntu.com/releases/18.04/release/
The file you're looking for should be named ubuntu-18.04-server-amd64.iso or similar (if there's a point release for example, it may be named ubuntu-18.04.x-server-amd64.iso where x is the point release number). The ISO image you download can be used in a virtual machine right away, or you can create a bootable media with which to install it on a physical machine. The process of creating a bootable flash drive was covered in Chapter 1, ...
