A software container is a standardized unit of software that packages up code and all its dependencies so the application runs quickly and reliably from one computing environment to another. A container is a standalone, executable package of software that includes everything needed to run an application: code, runtime, system tools, system libraries, settings. Containers are isolated from each other and bundle their own software, libraries, and configuration files; they can communicate with each other through well-defined channels. By contrast, virtual machines (VMs) package up an application with a full copy of an operating system (OS), which can be many gigabytes in size. Because they don’t need a full OS, containers are much more efficient in terms of disk space
Some of the emerging trends in software containerization include the use of containers for microservices, the use of containers for serverless computing, and the use of containers for cloud-native applications.