template data
process reprocess
output HTML output display

Process the template, upper left, with the data, upper right. See the resulting DOM in output display, lower right, and the corresponding HTML text in output HTML, lower left. Notice, however, that the template processing happens directly on the HTML DOM, and the HTML text shown is merely the innerHTML of that DOM.

Now, change the data and reprocess the DOM of the output display with the changed data, and see that the output display reflects the change. Notice that the reprocessing takes place on the DOM of output display, i.e. on the result of the previous template processing.