Mansour, would containers be used for things like maps and other scripts (accordians, sliders, forms)?
<p>Our location and directions:</p>
<div class="map"> <<< container
( Google Map Here )
<p>Call for more info!</p>
For a map, you would use the HTML Element. While it is a container itself, it is used to insert custom HTML and scripts to a page.
As Mansour pointed out a container is just a way to place a div within a div. It can be used in many different situations but mainly is used to provide more control over positioning of different elements within a design.
Such as adding an image with a figure comment below it, wrapped around a paragraph or to add a different colored background to an already colored column:http://www.coffeecup.com/files/articles/container-example.jpg
One thing to note though, is that in support we have seen many people adding containers to a column or adding a sub-grid and not using them. While this will not hurt the visual aspect of your design, it is adding extra code to your page that is not needed. So the one suggestion we give is, to use the container element only when needed.