Conceptually, a container image can be thought of as a snapshot of a container's filesystem that can be stored on disk. The container filesystem is typically arranged in layers and every change gets carefully captured in a separate layer. This allows the container image to indicate from which parent image it is derived. The Docker images, being represented through a standardized and simplified format, can ultimately lead to the rapid and rewarding deployment and execution of software applications. Containers are portable. This means that building images once and running them everywhere is the crux of the portability goal. Containers can run on any hardware that runs the relevant operating system.

There are challenges too. As there can be many containers in a single Docker host, there can be the issue of the container sprawl in a cloud environment (private, public, and hybrid). For effective monitoring and management, the concepts of clustering and orchestration are being leveraged in order to find and bind different and distributed containers. Further on, for constructing distributed applications through containerized applications, service composition through the orchestration technique is encouraged. Docker Compose is the key solution for making composite applications. For working at the container level, there are automated monitoring, measurement, management, and orchestration software solutions (Docker Swarm, Kubernetes, and Mesos). In the following sections, we explain how containers are the best fit for agile and adroit businesses. This does not mean that virtualization is out of business. There are certain situations and scenarios wherein the mixed and merged usage of virtualization and containerization is posted for wonders.

Combining these special powers with container images, resulting in a viable and venerable abstraction, enables a clean isolation between applications from the underlying operating systems. This neat decoupling of image and OS makes it possible to deploy software applications in development, testing, staging, and production environments without any hurdle or hitch. This Docker-enabled uniformity and ubiquity improves deployment reliability and speeds up modern enterprise development by decimating all kinds of inconsistencies and unnecessary frictions. The widely expressed recommendation is to have an airtight container image that can encompass and encapsulate all of an application's dependencies into a package. This then can be deployed into a container to enable shipping to run anytime anywhere.