About editing wiki pages?

In this page:http://en.wikipedia.org/wiki/Template:X1

It says:

If you defined parameters such as {{Template sandbox|First|Second|name="Named"}}:

First
{{{1}}}
Second
{{{2}}}
Name
{{{name}}}

What is it talking about? What are these parameters used for and how can they be used?

Thank you very much.

Templates are used for repeating data across pages. A template like the one you described could be used to display biographical information on a person. If you have a box that you want to use across several pages, you can set it up like:

First name: {{{first}}}
Middle name: {{{middle}}}
Last name: {{{last}}}

You would make a special page that looks like this called "Template:Name", for instance. Then, if you wanted to a page about George Bush, you could add it just by doing this:

{{Template:name(or you could just use "name"|first="George"|middle="Walker|las...

The numbers are just a way of outputting data from one template and using it inside another template. They are usually only used for rather complex templates.