Not able to find garmin.openstreetmap.gl.
I think that was a typo by Seldom

- .gl should have been .nl - try this:
http://garmin.openstreetmap.nl/The maps at that URL will be in Garmin's vector format (.img files). Vector and raster maps serve different needs. Assuming that the data is accurate, vector maps don't degrade as you zoom in. If the author defines a line as 2 pixels wide, it will always be 2 pixels wide at every zoom setting and 9 point text will always appear as 9 points on the screen. This can be either good or bad, depending on what you want.
Raster maps are images, so if a line is created to be 2 pixels wide when the map is viewed with a zoom setting of 1 mile, then it will get fatter and "jaggier" when you zoom farther in. Same thing with text, it is scaled for one specific zoom setting.
But since they are just images, raster maps can be made from aerial photography or scanned paper maps. OSM maps are available in raster format as well - for a simple example, just go to
http://www.openstreetmap.org/ The map you see is made up of PNG image "tiles" - you can right-click on the map and view the individual tiles in your browser, like this:
