Docker is a popular platform used by developers to ship, and run applications in containers. Containers are lightweight, portable, and standard unit of software that packages  applications and all its dependencies like libraries, binaries, and configuration files into a single image.

In Linux, the hostname refers to the name assigned to a computer or device on a network. It's used to identify the system within a network environment. The hostname can be a simple name, typically a single word, or it can include domain information, forming a fully qualified domain name (FQDN).