Containers vs Virtual Machines(VM)

Containers and virtual machines (VMs) are both technologies used for virtualization, but they have some key differences in terms of architecture, resource utilization, and deployment.

Main distinctions between containers and virtual machines

1. Architectural Differences:

   • Containers: Containers virtualize the operating system (OS) at the application level. They encapsulate the application and its dependencies, such as libraries and binaries, into a single, lightweight unit. Containers share the host OS kernel but run in isolated user spaces.
   • Virtual Machines: VMs virtualize the entire hardware stack. Each VM includes a full OS, a hypervisor, and the application. Multiple VMs run on a host machine, and each VM has its own dedicated OS instance.

2. Resource Utilization:

   • Containers: Containers are more lightweight compared to VMs. Since they share the host OS kernel, they have lower overhead in terms of memory and disk space. Containers can start quickly and use fewer resources because they don't need to duplicate an entire OS for each instance.
   • Virtual Machines: VMs are heavier in terms of resource usage because they include a full OS for each instance. VMs typically have longer startup times and higher resource requirements compared to containers.

3. Isolation:

   • Containers: Containers provide process-level isolation. They share the OS kernel but run in separate user spaces, which isolates the processes and filesystems.
   • Virtual Machines: VMs provide stronger isolation since they have their own complete OS. The hypervisor ensures that VMs are isolated from each other at the hardware level.

4. Portability:

   • Containers: Containers are highly portable across different environments. As they encapsulate the application and its dependencies, they can run consistently on any system that supports containerization, regardless of the underlying infrastructure.
   • Virtual Machines: VMs are less portable due to their larger size and the need for virtualization support on the host machine. Moving VMs between different hypervisors or cloud platforms can be more complex.

5. Performance:

   • Containers: Containers generally have lower overhead and better performance than VMs. They share the host OS kernel, resulting in faster startup times and efficient resource utilization.
   • Virtual Machines: VMs have a higher overhead due to the need for a full OS for each instance. This can lead to longer startup times and increased resource consumption.