Not used them personally but I believe that they’re native to Dreamweaver.
I think that if you create a site in Dreamweaver using templates then it will create a .tpl file which you can then enable editable regions and it will output things like header, navigation, footer etc that are consistent across a site.
Obviously this only has the benefit to Dreamweaver users so I’d personally just use something like PHP to include separate PHP files instead as it’s much more flexible and doesn’t rely on one bit of software
In that case I’m guessing that it’s just a PHP file that’s being used as a template for other PHP files to use.
A PHP file could be called a .inc or .tpl so it doesn’t have to have a .php extension.
I presume that the file extension is used so that the author can easily recognise which files are being use as templates, which are includes etc
I’d never go looking for a reason to use something that I don’t understand though. If you don’t know what a .tpl file is or when you need to use it then my guess is that you don’t actually need it
I’d always suggest designing a solution for a problem and not using a solution to find a problem
Nothing wrong with asking questions about things you don’t understand, it’s the best way to learn.
A lot of people do find something neat that they like the look of though and then going and trying to look for a problem to solve with it which is usually the wrong way to approach things.
Albeit *.tpl is a generic file extension usually (when concerning web) and typically gets used for PHP files that are templates for forums although the extension is irrelevant really – usually it just makes it easier for the webmaster to recognise a file’s purpose if he so choses.
It could be equally as well be called *.dog or *.zog it makes no difference other than it gives us a clue if it looks like and abbreviated word, e.g. *.inc for include.