I came across this question. I see that both stickyHeader and scroller works kind of the same in the way that they both keep the header row visible and there's a scroller bar on the side. Could someone please kindly explain the difference between them?
The stickyHeader widget makes the table head "stick" to the top of the browser, or table container (if options are set), window as the user scrolls down the table; this is similar to the sticky menu some sites use for site navigation. Check out this demo especially the last one on that page which is an example of nested tables stacking the sticky headers while you scroll down the document. There is also a css3 version of this widget which uses css3 transforms to position the table head at the top of the browser window.
The scroller widget, on the other hand, has to make a copy of the table header placed above the table, hides the original table header, then makes the tbody of the table scrollable, within a fixed height. So, the browser window position doesn't change which the user is scrolling through the table content, just a scrollable window of content is seen. If you look at this demo, you'll see that the table body is scrollable, but the head does not "stick" to the browser window (unless you set the scroller_jumpToHeader which forces the table head to become visible while scrolling up the document.