What Is Docker, How It Works and Its Advantages

If you're interested in software development and programming, you've undoubtedly already wondered what Docker is.

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

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

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

What is Docker

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

With all the tools that compose it, it's possible to execute these environments efficiently and in an optimized manner.

This technology also allows any team to operate and have access to the functionalities of the system and server infrastructure, without needing any special permissions.

After all, we can compare its application to that of virtual machines (VMs). The difference is that it's also compatible with cloud storage.

These characteristics greatly facilitate collaborative work among professionals and developers, contributing to the flexibility and agility of deliveries.

Understand what Docker does

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

Any Docker files can be "packaged", or gathered, into containers, and can be transported from one environment to another in a simple and fast way. Thus, portability is one of the most striking characteristics of Docker.

What are the advantages of using Docker?

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

We've selected at least 5 advantages of using Docker technology in your daily work. Check them out!

Community with repository

There's a large community with a huge Docker image repository, with ready-made models for adaptation.

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

You just need to give your "finishing touch" to the images and add any configurations and adaptations your system may need.

Infrastructure and Development with the same language

Having one language for both infrastructure and development in Docker was, until then, impossible.

Many problems and impasses arose due to language divergence. But they were mitigated with a common language.

Similar environments

You just need to transform a file into a Docker image and it can be stored and transported to any container. There are several possible environments to keep your file in.

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

All application and dependencies in one package

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

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

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

When a file is modified, you just need to execute a few Docker commands so that the update also happens in the downloaded files.

Time savings with Docker environment replication

With so many functionalities, it's clear that the user or professional will save time. Another useful feature is the standardization and replication possibility that the system offers.

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

Complete Docker guide: understand what containers are

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

This, in turn, allows each layer to be executed separately, optimizing system time and configurations.

When it's necessary to execute development layers simultaneously, Docker container technology is the most recommended.

Complete Docker guide: understand what images are

Docker images are the files that build the application, which is usually made in layers.

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

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

Thus, it's as if the process always depends on an image to run 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 is the purpose, if they have access to complete images, with exact file packages. 

Containers, when running, are capable of maintaining one task at a time, with one responsibility per container. 

Even though it may seem like a very complicated topic at first glance, learning about virtualization on Linux and understanding Docker's inner workings is not impossible. 

You just need to find the right content, didactic and applicable — after all, you want to learn how to apply this knowledge to make your daily life easier, right? 

If the answer is "yes", know that the Certificação Linux team can help you! 

We offer a complete Docker course, which can be the missing key turning point for those working with DevOps. It's worth checking out this and other courses we've prepared for you! 

Certificação Linux: Linux courses with a fully didactic and applicable structure. Boost your career. Click and learn more!

Conclusion

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

As you may have noticed, there are several advantages to using the methodology, such as process optimization and time savings, increasing productivity. 
If you like studying and understanding topics related to IT and Linux careers, you need to check out the other articles on the Certificação Linux blog!