You can use vSphere Lifecycle Manager to customize an ESXi base image by adding vendor add-ons and additional components. Depending on your goal, a vSphere Lifecycle Manager image can be distributed and consumed in three different formats.
ISO Image
Distributing an image created with vSphere Lifecycle Manager in an ISO format is useful when you need the image to perform clean installs of ESXi and for bootstrapping purposes, for example the kickstart workflow.
You cannot use an image exported as an ISO file with another cluster that uses vSphere Lifecycle Manager images.
You can import the ISO image into the local depot of the target vSphere Lifecycle Manager instance, but you can only use the ISO file to create upgrade baselines. You cannot use ISO files with vSphere Lifecycle Manager images.
ZIP File
Distributing an image created with vSphere Lifecycle Manager as an offline bundle is useful when you want to import the components that the image contains into the depot of the target vSphere Lifecycle Manager instance.
Unlike the ISO image, you cannot use a ZIP file to create upgrade baselines.
JSON File
Distributing an image created with vSphere Lifecycle Manager as a JSON file is useful when you want to reuse the same image for other clusters that use images for host management.
When you distribute the JSON file to clusters in a different vCenter Server instance, you must make sure that the depot of the target vSphere Lifecycle Manager instance contains all components that the JSON file contains.
The JSON file contains only metadata and not the actual software payloads.
