Containers versus VMs (virtual machines)

Containers are lightweight, portable, and self-contained executable images that contain software applications and their dependencies. They are used to deploy and run applications in a consistent way across different environments, such as development, staging, and production. Containers are typically deployed from an image by using an orchestration platform, like Kubernetes. These platforms provide a way to manage and deploy containers at scale.

Containers have a number of benefits over traditional virtualization methods. As they are more lightweight and portable than VMs, containers support decomposition of a monolith into microservices. Containers are faster to manage and deploy than VMs, which can save time and money with application deployment.

Virtual machines (VMs) or guests represent instances of an operating system co-located on a physical machine through the use of a hypervisor. Each VM has its own operating system, memory, and other resources, which are isolated from the other VMs on the same physical computer. This allows multiple operating systems to run on the same physical components without interfering with each other.

Virtual machines are created and managed using hypervisor software. A hypervisor is software that manages a physical computer's resources and allocates them to virtual machines.

Virtual machines access the hardware of a physical machine through a hypervisor. The hypervisor creates an abstraction layer allowing the VM to access CPU, memory, and storage. Containers, on the other hand, represent a package that includes an executable with the dependencies it needs to run.

This means that each container shares the physical machine's hardware and operating system kernel with other containers.

As a result, virtual machines are typically more resource-intensive than containers. However, virtual machines also provide a high level of isolation, which can be important for security and compliance reasons. Containers are more lightweight and portable than virtual machines. This makes them a good choice for applications that need to be deployed quickly and easily, where compute must be optimized.

See the comparison chart to further understand the differences between containers and virtual machines:

To understand the differences between containers and VMs, it's helpful to visualize their architecture:

• Containers:
• Share the host OS kernel: Containers leverage the underlying operating system kernel of the host machine.
• Lightweight: Smaller in size and require fewer resources compared to VMs.
• Faster startup: Start and stop quickly due to shared OS kernel.
• Virtual machines:
• Run a full guest OS: Each VM has its own dedicated operating system, isolated from other VMs.
• Resource-intensive: Require more resources (CPU, memory, storage) compared to containers.
• Slower startup: Take longer to boot up due to the need to load the guest OS.

While containers and virtual machines serve different purposes, they are not mutually exclusive. In fact, they can often be used together to create a powerful and flexible infrastructure.

• Containers are segregated applications or services on a host and share the same operating system
• Virtual machines are isolated instances of an operating system on a physical host and run applications or services

Containers have a smaller footprint than virtual machines. This is because containers share the host operating system's kernel, while virtual machines each have their own kernel. As a result, containers can start and stop faster, and they use fewer resources.Virtual machines are isolated from each other, which can help to prevent attacks from spreading between guests.

Containers are a popular choice for a variety of use cases, including:

• Web development: Containers are a good choice for web development because they can be easily deployed to a variety of environments, such as development, staging, and production
• Microservices architecture: Containers are a good choice for microservices architecture because they can be used to deploy and manage individual services
• Cloud computing: Containers are a good choice for cloud computing because they can be easily scaled up or down to meet demand
• Continuous integration and delivery (CI/CD): Containers can be used to support automated processes of building, testing, and deploying applications

Containers are a powerful tool that can be used to improve application development, deployment, and management. They are a good choice for a variety of use cases, and are becoming increasingly popular in the cloud computing industry.

Virtual machines are a popular choice for a variety of use cases, including:

• Testing: Virtual machines can be used to test new software in a safely sandboxed environment. This is because the VM can be easily reset or deleted if the software causes problems.
• Development: Virtual machines can be used to develop software on different operating systems. This can be useful for developers who need to test their software on different operating systems, or for users who want to use different operating systems for different tasks.
• Isolation: Virtual machines can be used to isolate applications from each other. This can be useful for security segmentation and resource partitioning.
• Cloud computing: Virtual machines are a popular choice for cloud computing because they can be easily scaled up or down to meet demand.
• Disaster recovery: Virtual machines can be used in support of disaster recovery strategies. This is because the VM can be easily restored from a backup if the host machine fails.

Virtual machines are powerful tools that can be used for various purposes. They are a cost-effective way to run multiple operating systems and applications on the same computer, and they can be used to test new software in a safe environment.

The choice between containers and virtual machines depends on your specific requirements. Here's a guide: