What is the difference between and in JavaScript

Question

When creating strings in JavaScript, the character'or the character " seem to have the same effect. So, what's the distinction between these two characters?

The only advantage I've seen in using'to construct strings is that I can do things like:

var toAppend = '<div id="myDiv1"></div>';

Instead of:

var toAppend = "<div id=\"myDiv1\"></div>";

Is there an important distinction between them that I should be aware of?