I have been trying to draw some UML diagrams for simple scenarios and I am new to this. Does use case realization model refer to the same as ECB entity-control-boundary pattern?
When you design a use case realization you quite often step into ECB (or MVC) to show how interactions in the system under consideration work. So you are looking at business entities and try to figure out how to represent them to actors and what to do with them. However, there are also systems which do not deal with business objects and therefore you will not model ECB (e.g. think of automates which control signals).