The equal operator (==) is probably the more commonly used and as we all know returns true if the two values being compared are equal. When the values are of different types it converts them to an appropriate type to do the comparison.
The strict equal (===) returns true if the values are equal and of the same type.
 == 1; //returns true
 === 1; //returns false
This can be useful information for those of us who spend time in Authorware script and Actionscript where things are a little bit different.