{jrCore_image} shows an image from the active skin's img folder, or from a module's. Use it rather than a fixed <img src>: when an admin replaces the image on the skin's or module's Images tab, the template shows the new one without changes. See Changing Skin and Module Images.
{jrCore_image image="logo.png" width="200" alt="My Site"}
{jrCore_image module="jrEmbed" image="spinner.gif" width="24" height="24" alt="working..."}
<div style="background-image:url('{jrCore_image image="bckgrd.png" src_only=true}')"></div>The URL points to Jamroom's image handler, not to the file, so it always serves the active image.