A contents template allows you to specify information that is relevant to all segments (or most of the segments) when you register a new video (this is useful if the video contains multiple segments). The information you specify is automatically used when you add new segments. You can also save a template to a file and reuse it later.
If you always want to use a contents template when adding new segments to a video, select the 'Use contents template' option in the Options window (Tools->Options->Data Entry).
If the video only contains one segment, there is no need to use a template.
You can also use a contents template to register information after all segments are added to the video. For example, if you only specified titles when you originally registered the video, you can assign a contents template to the segments on the video at a later time. This allows you to register information for all segments on the video in one operation.