Cacti templates are broken into two areas:
In the above figure, under the Templates section, you will see the three types of templates that come with the Cacti basic installation. If you click on one of those links, you will get the complete list of templates for that type.
Graphs are used to visualize the data you have collected. A graph template provides a skeleton for an actual graph. When you have more then one system/device, a graph template will save you lots of time and also reduce the possibility of error. Any parameters defined within a graph template are copied to all the graphs that are created using this template.