In the last few articles we discussed about containers and dockers.
Docker images and containers are the core objects of the Docker as an ecosystem. In this articles, lets discuss more about Docker images and containers.
Let's start by reviewing what Docker is. In layman's terms, Docker is a cargo ship with the ability to hold containers with specific objects and IDs. These containers contain special items that are necessary to make the particular container functional for the business or person who has requested it be shipped.
Docker Image
Now let's see what is Docker Images. Docker images are ready-to-use, read-only templates for software applications that have all the source codes, libraries, external dependencies, tools, and other necessary files to run properly on any platform or OS.
You can manually build images using a Dockerfile. A Dockerfile is a text document containing all the commands to create a Docker image. You can also pull images from a central repository called a registry, or from repositories like Docker Hub using the docker pull command.
The image relies on the host operating system (OS) kernel. For instance, to build a web server image, begin with an image that includes Ubuntu Linux (a base OS). Next, layer on software like Apache and PHP. When a user runs an image, it becomes one or multiple container instances.
Since Docker images are immutable, you cannot modify them after they have been produced. If you need to change something, create a new container with your edits, then save it as a different image. Alternately, you could simply run your own container using an existing image as a base and modify that.
What is a container?
Now that you have got hold of the docker image concept it will be appropriate to describe the docker container now. A container is an isolated place where an application runs without affecting the rest of the system and without the system impacting the application. The container is lightweight and doesn't use more memory than other executables because it operates natively on Linux and shares the host machine's kernel. Since containers don't require the overhead of a whole operating system, they can be significantly more efficient than virtual machines. They share a single kernel with other containers and boot in seconds instead of minutes.
An application can be packaged in containers with all of the necessary components, and then shipped out as a single unit. This method is well-liked because it makes it easier to move quickly from the development environment to the testing and production environments.
How do Docker Images Differ from Containers?
The key difference between a Docker image and a container is, A Docker container is a runtime instance of a Docker image that gets created when the docker run command is implemented. You can create many containers from the same image, each with its own unique data and state. Images are a popular technique to make containers, yet they are not the only option.
Before the docker container can even exist docker templates/images are built using docker build CLI.
Docker image templates can exist in isolation but containers can't exist without images.
You can utilize the Docker platform to its full potential now that you are aware of the differences between Docker images and containers.
Choosing containers or images is not necessary. To use Docker, you need both of them because they depend on one another. Although Docker images and containers have a similar purpose, they have different uses. An image is a snapshot of an environment, and a container runs the software.
I hope you find this article informative.
Thank you for reading!
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