The Container represents a lightweight, standalone, executable package of software that includes everything needed to run it: code, runtime, system tools, system libraries, and settings. The most prominent container technology is Docker. The key concept of a container is that it virtualizes the operating system, allowing it to run on any infrastructure. This differs from a traditional virtual machine (VM), which virtualizes the underlying hardware. Because containers share the host system's OS kernel, they are much more lightweight, start up faster, and use fewer resources than VMs. For software development and testing, this provides a powerful advantage: consistency.
A developer can create a containerized application for controlling a programmable power supply, packaging the control script (e.g., in Python), all its dependencies (like the PyVISA library), and specific configuration files into a single container. This container can then be shared with other team members or deployed to a test server, and it will run in exactly the same way regardless of the underlying host machine's configuration. This solves the classic "it works on my machine" problem.
In automated test environments for electronics, containers can be used to create isolated, reproducible test setups, ensuring that each test run is independent and not affected by other software running on the system.