Question: I know this isn't a code issue related question, but it's something I'd love to know and it may help others:

What's the difference between using this:

```
$(function() {
    var $fullArea = $('#full-sized-area');
    var $fullContent = $('#full-sized-content', $fullArea);
});

```

Over say this:

```
$(function() {
    var $fullArea = $('#full-sized-area');
    var $fullContent = $('#full-sized-content, #full-sized-area');
});

```

Answer: 
Both are diffent here..

```
$(function() {
    var $fullArea = $('#full-sized-area');
    var $fullContent = $('#full-sized-content', $fullArea);
});

```

This one select element which has id "full-sized-content" under the #full-sized-area element

```
$(function() {
    var $fullArea = $('#full-sized-area');
    var $fullContent = $('#full-sized-content, #full-sized-area');
});

```

This one select both element with the ID full-sized-content and full-sized-area
Your code:

```
var $fullContent = $('#full-sized-content', $fullArea);

```

it says find me `#full-sized-content` in `$fullArea`, because of the `,`. `,` makes a context for this.

---

This code:

```
var $fullContent = $('#full-sized-content, #full-sized-area');

```

is usually called a **muliple selector selection** which is a string with `,` separated elems while below 

```
var $fullContent = $('#full-sized-content', $fullArea);

```

is usually finds an element in a given context which is `,` separated elems.