What is Docker?
Docker is an open platform for developing, shipping, and running container-based applications. Docker enables you to separate your applications from your infrastructure so you can deliver software quickly. Originally built for Linux, Docker now runs on Windows and MacOS as well. With Docker, you can manage your infrastructure in the same ways you manage your applications.
"451 Research predicts that "the application container market will explode over the next five years. Annual revenue is expected to increase by 4x, growing from $749 million in 2016 to more than $3.4 billion by 2021, representing a compound annual growth rate (CAGR) of 35 percent." (Source)
Docker can get more applications running on the same hardware than other technologies; it makes it easy for developers to quickly create ready-to-run containered applications and it makes managing and deploying applications much easier.
"Docker is a platform which packages an application and all its dependencies collectively in the form of containers. And, Docker’s aspect of containerization ensures that the application can work in any environment." (Source)
Dockerfile - A text document that contains all the commands that a user can call on the command line to assemble an image is known as a Dockerfile
Docker Swarm - To create and maintain a cluster of Docker Engines, Docker Swarm is a technique. Docker engines can be hosted on different nodes, and these nodes (present in remote locations) form a Cluster when connected in Swarm mode.