This is my revision for CKAD exam. I used three sources for my revision. Sanders: Optional for CKAD revision Mumshad: Essential for CKAD revision Killer.SH Lesson 1: Understanding and Using Containers 1.1 What is a Container Containers are Linux! Linux Kernel Namespaces provide strict isolation between system components at different level. Isolation at: network, file, users, processes, and Inter Process Communication.