A Docker image is a read-only template that contains a set of instructions for creating a Docker container. It includes everything needed to run an application, such as the application code, libraries, dependencies, and the runtime environment. Docker images are composed of multiple layers, each representing a specific modification to the file system, such as adding or modifying files. These layers are immutable, meaning once they are created, they cannot be changed. Instead, new layers can be added on top to create a new image version[1][2][3][4][5].
Key characteristics of Docker images include:
Immutability: Once an image is created, it cannot be modified. Any changes require creating a new image or adding new layers on top of the existing image[2][5].
Layered Structure: Docker images are built in layers, with each layer representing a change to the file system. This layered approach allows for efficient storage and reuse of common layers across different images[1][3][4].
Portability: Docker images can be shared and distributed through container registries like Docker Hub, making it easy to deploy applications consistently across different environ...
