Shim=Shiv (latest http://cdnjs.com/libraries/html5shiv)
Kind of like polyfills cover over the differences in implementations of features.
The way the HTML5 shiv works requires you to put it in the <head> element
Also refer to excellent reference on Html5 polyfilling
https://github.com/Modernizr/Modernizr/wiki/HTML5-Cross-Browser-Polyfills