When you start a new release definition, or when you add an environment to an existing release definition, you can choose from a list of templates for each environment. These templates pre-populate the environment with the appropriate tasks and settings, which can considerably reduce the time and effort required to create a release definition.
A set of pre-defined environment templates are available in Team Services and in each version of TFS. You can use these templates when you create a new release definition or add a new environment to a definition. You can also create your own custom environment templates from an environment you have populated and configured.
Templates do not have any additional security capability. There is no way to restrict the use of a template to specific users. All templates, pre-defined and custom, are available for use by all users who have permission to create release definitions.
When an environment is created from a template, the tasks in the template are copied over to the environment. Any further updates to the template have no impact on existing environments. If you want a way to easily insert a number of environments into release definitions (perhaps to keep the definitions consistent) and to enable these environments to all be updated in one operation, use task groups instead of environment templates.
Can I export templates or share them with other accounts or projects?
Custom templates that you create are scoped to the team project that you created them in. Templates cannot be exported or shared with another team project, collection, server, or account. You can, however, export a release definition and import it into another project, collection, server, or account. Then you can re-create the template for use in that location.
Can I publish or consume new templates through extensions in VS Marketplace?
How do I update a custom environment template?
To update an environment template, save the environment in a release definition as a template with the same name. This overwrites the original template.