I saw two topics about that but I'm still not sure.
I'm discovering Magento 2, I'm a frontend developer and right now, I just want to make my company website's header and footer (html, css) (so a theme)
Which folder should I use ?
If I'm creating a new module, I have to create all phtml files, layout, etc... in
app/code/../view/frontend/templates/xx.phtml but if I'm overriding an existing module, eg : module-theme or module-catalog, I'm doing it in