[OpenLayers-Users] What does the projection do in OL

[maven apache]

Hi:

I wonder what is the responsibility of projection in OL?

Since I have our own map data which use the no-epsg:4326 projection, then
we use the ESRI arcgis to generate the tiles and depoly them through the
wmts service.

The generated tiles cover 20 levels each have a resolution.

Now  I want to add the layer to the map.

So I use this manner:

var lay=new OpenLayers.Layer.WMTS({

 resolutions:[1.4,0.7........],
 url:'',
 ......
 tileOrigin:new OpenLayers.LonLat(-180,90)
});

map.addLayer(lay);

It works. But as far as I know the default projection of the map is
"EPSG:4326", while our layer is not. But it worked. Why? I have not make
any projection translation.

Then I want to know what does the projectin do in OL?
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/openlayers-users/attachments/20130711/2cc00b2a/attachment.html>