Definition
Containerization is a method of packaging software applications and their dependencies into isolated, portable units called containers. These containers ensure that an application runs consistently across different computing environments, from a developer's laptop to a production server. It works by virtualizing the operating system, allowing multiple containers to share the host OS kernel while maintaining their own isolated file systems, processes, and network interfaces. This technology is crucial for modern software development and deployment, enabling faster release cycles, improved scalability, and efficient resource utilization. For example, a web application can be containerized with its web server, database drivers, and libraries, making it easy to deploy and manage anywhere. Unlike virtual machines which virtualize hardware, containers virtualize the operating system, making them much lighter and faster. Containerization concepts are frequently tested on cloud certifications like AWS Certified Solutions Architect and in project management exams such as the PMP.