Templates are defined by a template control file. This file is a JSON file that defines the files that should be copied into the package directory. It also defines how the files should be processed during that copying.
A very common use case is that you want to use a template that is very similar to an existing template, but you want to make a few changes. The most common is to change a version of a dependency, or to add new dependencies.
To do this, you can use the laoban admin updatetemplate command. This will create a new template that is a copy of an existing template.