Developing a MVC Component/Adding backend actions

It's not clear to me where the word "helloworld" refers to in these examples. Can you please clarify when 'helloworld' refers to the component,controller,model,table,view or form? While following this, I've changed the name of my component, and when running this I get a 'call to member function getTable() on non-object'. It seems that I used the wrong name somewhere, but I have no idea where.