when do we need to know the different tags vs using a pre-determined template? could you give another example of using a loop with EJS? How do partials work if we want the nav bar to look different on different pages? For example if we want to highlight the page we're on. Can we see more use cases for partials? Could you clarify the difference between escaped and unescaped data? / can you talk more about escaped vs. unescaped values? / When would we use the "unescaped" data over the "escape data? (Basically when should we use <%- over <%=)