What is Docker, how does it work and what are the advantages

If you are interested in software development and programming, you must have undoubtedly wondered what Docker is.

After all, this is a widely used methodology that optimizes the entire teams’ work process. It’s no wonder that he stood out so much among professionals.

Despite knowing about its fame, you may wonder what are the advantages of using Docker, what are containers, images, and what is the difference between these terms.

To help you discover the answers, we from the Linux Certification team developed this complete content, with everything about what Docker is and what are the benefits of using it. Come check it out!

What is docker

An open source platform, Docker enables the virtualization and creation of isolated environments, or containers on Linux.

With all the tools that comprise it, it is possible to execute these environments efficiently and optimally.

This technology also allows any team to operate and have access to system and server infrastructure functionalities without needing any special permission.

After all, we can compare your application with that of virtual machines (from English, Virtual Machine or VM). The difference is that it is also compatible with cloud storage.

These features make it much easier for professionals and developers to work together, contributing to the flexibility and agility of deliveries.

Understand what Docker does

Photo: Unsplash | What does Docker do?

Docker uses standard Linux kernel resources for its execution. This makes your processes independent, with the possibility of being operated individually and simultaneously.

Any Docker files can be “packaged”, or bundled together, in containers, and can be transported from one environment to another simply and quickly. Thus, portability is one of the most outstanding features of Docker.

What are the advantages of using Docker?

There are several advantages to knowing what Docker is and how to use it. Mainly IT professionals who develop applications, or work with isolated environments.

We have selected at least 5 advantages of using Docker technology in your daily work. Check it out!

Community with repository

There is a large community with a huge repository of Docker images, with templates ready for adaptation.

From infrastructure pillars to integration systems, it is possible to find original images in the repository, already configured and duly regulated.

All you have to do is put your “finishing touch” on the images and add any configurations and adaptations that your system needs.

Infrastructure and Development with the same language

Having a language just for infrastructure and development in Docker was, until then, impossible.

Many problems and impasses have arisen due to the divergence of languages. But they were softened with a common language.

Similar environments

Just transform a file into a Docker image and it can be stored and transported to any container. There are several possible environments for maintaining your file.

It is also possible to integrate the database with the container and create an even more complete and functional structure. This option is highly useful for those testing in different environments or servers.

The entire application and dependencies in one package

No more struggling with each file in one place! With the Docker methodology, you can have all applications and dependencies in one package.

You just need to make sure that the images are easily accessible, and make the execution configuration available to users who download the file.

Phases such as storage and updating are also possible with Docker. After all, it is possible to keep several versions of the same image in the container.

When a file is modified, it is enough to execute a few Docker commands for the update to also take place on the downloaded files.

Saving time replicating the Docker environment

With so many features, it is clear that the user or professional will save time. Another utility is the standardization and possibility of replication offered by the system.

To reproduce them faithfully, the images must follow all construction practices during their structuring process.

What is Docker in full: understand what containers are

Containers represent the virtualization of an isolated environment within the Linux operating system kernel.

This, in turn, allows each level to run separately, optimizing system time and settings.

When it is necessary to execute development layers simultaneously, Docker technology in containers is the most suitable.

What is Docker in full: understand what images are

Photo: Unsplash | What are docker images?

Docker images are the files that build the application, which is generally done in layers.

The images are responsible for storing all the information that a process needs to be executed, such as:

• libraries;
• file systems;
• packages and resources;
• kernel modules, and more.

Thus, it is as if the process always depends on an image to be executed correctly, bringing significant results to the user.

Docker container and docker image, what’s the difference?

While the image is like a file responsible for storing all the necessary information, the container corresponds to the process that is executed by it.

Each image can create more than one container and they can only be virtualized, as proposed, if they have access to complete images with exact file packages.

Containers, when running, are able to maintain one task at a time, with one responsibility per container.

Although it seems like a very complicated subject at first glance, learning about virtualization on Linux and thoroughly understanding how Docker works is not impossible.

You just have to find the correct, didactic and applicable content — after all, you want to learn how to apply this knowledge to facilitate your daily life, don’t you?

If the answer is “yes”, know that the Linux Certification team can help you!

We offer a complete Docker course, which may be the missing turnaround for those who work with DevOps. It’s worth checking out this and other courses we prepared for you!

Linux certification: Linux courses with a fully didactic and applicable structure. Jump-start your career. Click and learn more!

Conclusion

Have you noticed how understanding what Docker is can make all the difference in your professional career?

As you can see, there are several advantages to using the methodology, such as process optimization and time savings, increasing productivity. If you like to study and understand more about topics related to careers in IT and Linux, you need to check out the other articles on the Linux Certification blog!

Uirá Endy Ribeiro

Uirá Endy Ribeiro is a Software Developer and Cloud Computing Architect with a 23-year career. He has master's degrees in computer science and fifteen IT certifications and is the author of 11 books recognized in the IT world market. He is also Director at Universidade Salgado de Oliveira and Director of the Linux Professional Institute - LPI Director's Board.