An image is a running environment template for ECS instances. It generally includes an operating system and preinstalled software. You can use an image to create an ECS instance or change the system disk of an ECS instance.

ECS allows you to easily obtain an image in the following ways:

• Choosing a public image officially provided by Alibaba Cloud (multiple Windows and Linux versions are available).
• Creating a custom image based on an existing ECS instance.
• Choosing an image shared by another Alibaba Cloud account.

You can import an offline image file into an ECS cluster to generate a custom image.

You can also copy a custom image to another region to maintain a consistent environment and application deployment across multiple regions.