A virtual machine, abbreviated as VM, is no different from any other physical computer like a smartphone, laptop, or server. It has memory, CPU, and disks to store files, and if needed it can connect to the internet. While the parts that make up your computer (called hardware) are physical, VMs are often thought of as virtual computers or software-defined computers within physical servers, existing only as code.

How does a virtual machine work?
Virtualization is creating a software-based, or "virtual" version of a computer, with dedicated amounts of CPU, memory, and storage that are "borrowed" from a physical host computer—like your personal computer.

Docker is an open-source freight platform. This authorizes developers to package applications into containers—systematize completable components combining application source code with the operating system (OS) libraries and dependencies required to run that code in any environment.

How Docker works
Docker works by giving a standard way to run your code. Docker is an operating system for containers. Similar to how a virtual machine removes the need to directly manage server hardware, containers virtualize the operating system of a server. Docker is installed on each server and gives simple commands you can use to build, start, or stop containers.

An IDE (integrated development environment) is software for building applications that combines common developer tools into a single  GUI (graphical user interface).

Why is an IDE important?

Throughout the process of creating, testing software, and writing developers employ a variety of tools. Code libraries, Text editors, compilers, bug tracking software, and test platforms are among the most common development tools. It combines development-related technologies into a single framework. It is also helpful for new developers who use an IDE to learn about a team’s standard tools. The aim of IDE is to make software development easier while detecting and reducing code errors and typos.