Pages is a word processor (like Microsoft Word) tool that helps you create documents. Using Pages, you may create and design your own templates. A template is a .Pages document type that copies of itself when you open this template file. Templates can be very useful if you frequently create documents that contain a lot of specialized design and text (like business letters, certificate documents, lesson plans etc). You may use templates as the basis of future documents. Pages includes built-in templates that are professional-looking. You may use the templates that come with Pages or you may want to create your own template. Here is how:
Built-in Pages templates
When you launch Pages, you may choose an existing template file you want to work from:
Pages has various word processing and page layout templates that you may use to create great looking documents. You may also modify these templates to create your own templates. You may modify page layout, colors, styles, headings etc. Then save the document as template (File menu and select Save as Template).
Design your own custom template
You can also start with a blank document and design your own unique template. To do this, the first things you may consider is general format like paper size, margins, headers/footers etc. A template must have various default values for tables, charts placeholders, texts etc. Launch a blank page and then set the page details (size, margins etc). You may want to add graphics, charts and texts. Create your own text box. Add images. Define your placeholders. Then save it as Template. More details can be found in the Pages User Manual.