Yes, this is true, but for beginners it is tough to add in the images dimensions when the often don't know how to determine it.
I should have added that if you know them, add the width and dimension parameters.
If you Right-click and View Image, the Browser window displays the pixel sizing on the Title bar at the top, along with the true Location Address of the image.
Try it:
The HTML:
<IMG SRC="http://www.freerepublic.com/images/frlogo.gif" width="150" height="130" border="2" ALT="www.FreeRepublic.com">
Cheers.