What is Docker?
Docker is an open source project designed to help with application deployment using software containers. This approach means running applications together with the complete environment (files, code libraries, tools, and so on). Therefore, Docker—similar to virtualization—allows an application to be packaged into an image that can be run everywhere.
Containerization versus virtualization
Without Docker, isolation and other benefits can be achieved with the use of hardware virtualization, often called virtual machines (VMs). The most popular solutions are VirtualBox, VMware, and parallels. A VM emulates a computer architecture and provides the functionality of a physical computer. We can achieve complete isolation of applications if each of them is delivered and run as a separate VM image.
The following diagram presents the concept of virtualization:
Figure 2.1 – Virtualization
Each application...
