So far in this book, we've covered the complete range of fully released interface widgets, as well as one still (at the time of writing) in its beta phase. Over the next four chapters, we're going to shift our focus to the core interaction helpers. These components of the library differ from those that we've already looked at in that they are not physical objects that exist on the page.
Instead, they give an object a set of generic behaviors to suit common implementational requirements. You don't actually see them on the page, but the effects that they add to different elements, and how they cause them to behave, can easily be seen. These are low-level components as opposed to the high-level widgets. There are currently five different interaction helpers, each catering for a specific interaction.
They help the elements used on your pages to be more engaging and interactive for your visitors, which adds value to your site and can help make your web applications appear...