Is flashing visually displayed like a pop-up in the browser?

How is redirect different from url_for? 

Are there situations where it's better to use abort() instead of flashing an error message and then redirecting the user? 

I'm also just a little confused about the purpose of app.secret_key. What does the secret_key part actually do?

Could we go over jinja2 inheritance a little more? / Can you please go over the example of inheritance containing the base template and child templates? / Can we go over inheritance again? Why do we never use head? / Can we go over another example of the jinja inheritance? / Can you please briefly go over template inheritance again? / Could you talk more about template inheritance? Thanks!


Can a child template inherit from multiple parent templates or just one?

I feel like I'm still trying to wrap my head around Jinja 2 but I'm sure I'll get a hang of it with more practise. 

was the cs304 website originally done one page by one page with no template?