Understanding Containers

Containers provide a method for organizations to distribute, deploy, and manage server applications more efficiently than with VMs. A VM virtualizes a full server environment, including both the application(s) and operating system environment (OSE), thus enabling a physical server to run multiple VMs simultaneously. However, having a full OSE for each VM (left side of illustration) running on a physical server often requires considerable server resources, potentially slowing performance and adding management overhead because each OS instance must be individually monitored, patched, and updated. 

Containers, by contrast, as shown on the right, leverage OS advances appearing first in Linux and subsequently in Windows Server that provide enhanced levels of isolation, naming, and resource controls for applications. These features allow a containerized application to achieve the same benefits as virtualization (including isolation and high application density on physical servers) with greatly reduced overhead. By removing the need for a separate OSE for each application, containers can be faster to deploy and launch than an entire VM.