In desktop publishing terms, a template is a pre-designed document that has the major design elements in place. You use a template by dropping in your custom and unique content, graphics, and other information.
Why use a template? Well, if you are not a graphic designer, you may have difficulty coming up with a good looking, professional design for your newsletter. Instead of struggling with this design work yourself, or having to hire someone to do it for you, you can use a template instead. Every time you need to produce a new issue, you open the blank template and fill in your articles, information, news, and pictures. Save it as your newest issue, and you're done!
Using a template means that you are able to keep the standard design elements and text that you need in each and every issue, without having to create the document from scratch or even having to change the prior issue's document. You can start with a clean slate each time you sit down to create the current issue.
Are there any downsides to using a template? Well, the reality is that you are not producing a truly unique newsletter, as someone somewhere could produce a very similar looking document. However, the chances of someone recognizing your template for what it is are very slim. And with your customization, it does become your own newsletter, unlike anything out there.
Using a template saves you time, money, and headaches. You get the benefits of a professionally designed newsletter without the work and cost.