What is a container image?

What is a container image?

• A. Container Image
• B. Virtual Machine
• C. Dockerfile
• D. Hypervisor

Answer: (A)

A container image is the packaged, portable artifact that contains everything needed to run an application inside a container: the application code, runtime, libraries, and dependencies, plus metadata about how it should run. It’s a static, read-only bundle that a container runtime uses to instantiate a container. The image does not include a full OS kernel; containers share the host’s kernel, which keeps images lightweight and fast to start. You build this image from a definition like a Dockerfile, and then store it in a registry so it can be pulled and run on any compatible host. This differs from a virtual machine, which includes a full guest OS with its own kernel, from a Dockerfile, which is just the set of instructions to build the image, and from a hypervisor, which is the software that runs virtual machines rather than containers.

A container image is the packaged, portable artifact that contains everything needed to run an application inside a container: the application code, runtime, libraries, and dependencies, plus metadata about how it should run. It’s a static, read-only bundle that a container runtime uses to instantiate a container. The image does not include a full OS kernel; containers share the host’s kernel, which keeps images lightweight and fast to start. You build this image from a definition like a Dockerfile, and then store it in a registry so it can be pulled and run on any compatible host. This differs from a virtual machine, which includes a full guest OS with its own kernel, from a Dockerfile, which is just the set of instructions to build the image, and from a hypervisor, which is the software that runs virtual machines rather than containers.