Docker is a platform that allows developers to package, deploy, and run applications in containers. A container is a lightweight, standalone executable package that includes everything needed to run an application, including code, runtime, libraries, and system tools.

Docker provides a way to isolate applications from the underlying infrastructure, which makes it easier to deploy and manage them across different environments. With Docker, developers can build applications in any language, package them in containers, and then deploy them on any infrastructure, whether it's a laptop, a server, or a cloud platform.

The main advantage of using Docker is that it provides a consistent and reproducible environment for running applications, regardless of the underlying infrastructure. This makes it easier to manage applications and reduces the risk of compatibility issues or runtime errors.

Here are some commonly used Docker commands:

1.  docker run: This command creates a new container and starts it.
   

2.  docker ps: This command shows all running containers.
   

3.  docker stop: This command stops a running container.
   

4.  docker rm: This command removes a stopped container.
   

5.  docker images: This command shows all available images on the system.
   

6.  docker pull: This command downloads an image from a registry.
   

7.  docker push: This command uploads an image to a registry.
   

8.  docker exec: This command runs a command inside a running container.
   

9.  docker logs: This command shows the logs of a container.
   

10. docker build: This command builds an image from a Dockerfile
    

Docker has become increasingly popular in recent years because of its ease of use, flexibility, and portability. It allows developers to quickly and easily create development, testing, and production environments, and it supports a wide range of programming languages and platforms.

Furthermore, Docker enables organizations to implement a microservices architecture, where applications are broken down into smaller, more modular components that can be easily deployed and managed. This can improve scalability, reliability, and agility, which are key factors in today's fast-paced software development industry.

Overall, Docker's growing popularity is driven by its ability to simplify and streamline the application development and deployment process, while also improving performance, reliability, and portability.