A template is a machine image defined in an image list.
A machine image is a copy of virtual hard disk with an installed operating system. You use a machine image to launch a virtual machine instance in Oracle Compute Cloud Service. The image must be a whole disk image (including a partition table and kernel) stored in a tar archive and compressed with gzip.
An image list is a collection of Oracle Compute Cloud Service machine images. Each machine image in an image list is identified by a unique entry number. You can group similar machine images in an image list for easy administration and usage.
When you upload a machine image using the web console, an image list is automatically created by using the name that you specified for the image. The new machine image becomes the default (and only) entry in the image list.
Oracle Public Cloud Machine provides two default Oracle Linux images, releases 5.11 and 6.5. These images are optimized for OPCM and include the essential packages that are necessary to get started using the instance that you create in Oracle Compute Cloud Service.
Note:
You cannot use any templates that are not based or developed from the OPCM default images.Public and Private Templates
The templates that are available for all the tenants in the cloud are referred to as public templates. Oracle Cloud Administrator uploads the public templates and are available under /oracle/public.
The templates are available only for you and other tenant users in the tenant are referred to as private templates. You and other tenant users in the tenant upload the private templates.