Custom component or Custom Tag?

[Former Member]

Hi. I'm confused when to use Custom Component (extends from an existing component like SimpleComponent) and when to use custom Tag.

Also, I found that in a sample template, a cart is made from component. But, at the same time it has its own tag to hold the component. Why don't we use HeaderRegion position to hold everything we need on top like menu, cart component, etc. Or... use custom CartTag which render the cart passed by the page controller.