What is a dynamic element?
A dynamic element is an element that its value can be changed dynamically, during run time. For example, let's say we have an unordered-list (ul) element with 100 list items (li). And let's also assume that all the li items are identical beside their text.
So, to avoid creating 100 different elements, you can easily create a single element, using XPath, and add a parameter to its value for changing the li's text.