A template is usually made of plastic
and has a pattern etched into the plastic or is a specific shape.
They can be used in a couple of ways.
As a plastic shape, they can be used as a tracing or cutting pattern for patches in quilt blocks.In the template set on the left, each piece represents a shape of a patch in a quilt block, and include the 1/4 inch seam allowance.
These are hard acrylic plastic, and can be traced around on your fabric. Or you can place the template on one or more layers of fabric and cut around the shape using a rotary cutter.
These are very handy to have because they are accurate, resist being cut with your rotary cutter, and are easy to find when you need them.
The little hole at the top of each template can be used to store them on a binding ring. These are available through amazon.com. If you click on the image, it will take you directly to the page on amazon.
A second kind of template is one that is used for quilting designs.
As
a quilting template, the patterns (slots) in the plastic are used to
assist you in keeping your design on target and make quilting easier. 
The template on the right is a machine quilting template for a Baptist Fan quilting pattern.
As you use this template, your machine will duplicate the quilting design, and you move the template as you finish one section of your quilt.
Templates for hand quilting are very similar. There are generally holes in the template so you can draw with a special pencil or marker or use a chalk pounce to duplicate the design on your quilt. That way, you can follow the lines of the design as you hand quilt.
Happy Quilting!
Penny Halgren
www.Hos-to-Quilt.com
www.QuiltBlockLibrary.com
www.TheQuiltingCoach.com
The template on the right is a machine quilting template for a Baptist Fan quilting pattern.
As you use this template, your machine will duplicate the quilting design, and you move the template as you finish one section of your quilt.
Templates for hand quilting are very similar. There are generally holes in the template so you can draw with a special pencil or marker or use a chalk pounce to duplicate the design on your quilt. That way, you can follow the lines of the design as you hand quilt.
Happy Quilting!
Penny Halgren
www.Hos-to-Quilt.com
www.QuiltBlockLibrary.com
www.TheQuiltingCoach.com