...
So for a product definition, we have two dimensions:
- Whether it is deterministic or part of an ensemble
- Whether the field is instantaneous or interval-based (e.g. accumulated)
So a A Product Definition Template Number of 8 means "deterministic and interval-based". If you chose 11 then your product would represent an ensemble member.
...
For the meaning of the various Product Definition Template numbers see http://apps.ecmwf.int/codes/grib/format/grib2/templates/4/.
You can also click on each entry to see the keys (contents) of the particular template e.g. For for template 11, see https://apps.ecmwf.int/codes/grib/format/grib2/templates/4/11.
...