What is the definition of a container in virtualization?

A container in virtualization is defined as an isolated user space that replicates the kernel's functionality. This means that containers share the host operating system's kernel while providing a lightweight and standalone execution environment for applications. Each container operates independently, allowing for isolation and resource control without the overhead of a full virtual machine.

Because containers utilize the same operating system kernel, they can start quickly and require less resource overhead compared to full operating system environments. This is pivotal for microservices architectures, where applications are split into small, manageable pieces that can be deployed and scaled independently.

The other options don't accurately describe containers: hardware-based virtualization refers to a different level of abstraction that uses hypervisors to create virtual machines; a full operating system environment characterizes virtual machines instead of containers; and a network security tool does not align with the core functionality of containers in virtualization.