7.3 Managing containers by using Kubernetes 7.3.1 Introduction to containers Images and containers This section provides an introduction to containers, the key points behind containers, and the  differences between containers and virtual machines. It also introduces Kubernetes for  container orchestration.  Containers represent a major technology shift for infrastructure management and application  development. It aims to simplify several application development activities while providing  better system resources utilization. Containers are a critical component that are present on  modern clouds in such a way that the union of containers with microservices applications is  the key component for an organization’s digital success. Similarly, the IBM LinuxONE platform is ready to meet the current and future growing  container requirements. When LinuxONE is used as the platform for hosting your cloud  services, it achieves excellent and unmatched scalability numbers when compared to x86  alternatives. Because of these reasons, the use of a container-based infrastructure also helps  to reduce costs by improving the overall infrastructure consolidation process, making  infrastructure management easier, and speeding up applications to market. Conceptually, a  container image  encapsulates that required runtime components of an  application, such as libraries, frameworks, and configuration files, along with the application  binaries and code. By doing so, it instantiates much smaller and self-capable containers that  can be scaled up on a single host, or scaled out across multiple systems. Because of these  factors, containers become the de facto infrastructure of choice for building and deploying  microservice applications. A container image is a collection of immutable layers that together contain all packaged  components that are required to run an application. An image can be shared across multiple  functional teams by using public or private registries. They also can be easily maintained and  updated to different needs. An image primarily consists of the following components: After an image is created and is ready to be distributed, it is then  instantiated  on what are  called containers. That is, while an image is a static representation of an application, a  container represents a running instance of such image. This method ensures application  consistency across various environments in such a way that the roll-out time from  development to production is greatly enhanced. Similarly, it also dramatically reduces human  errors during the application configuration, deployment, and implementation steps. The practice of creating and distributing container images and running containers from them  is also referred as  containerization . GLYPH<SM590000> An application GLYPH<SM590000> Its dependencies, libraries, and other binary files GLYPH<SM590000> Configuration files that are needed to run it 202  Securing Your Cloud: IBM Security for LinuxONE