/ = list page
/section-name/ = list page
/section-name/article-url-title = detail page

On any given page, the <txp:article /> tag works out which mode it’s in from the page url.

Using this tag in its simplest form will display 10 articles using forms/article/default.txp. In a default TXP install, this form distinguishes which mode its in (thumbnail for list, full article for detail).

all-grid instead uses separate forms for thumbnails <txp:article listform="thumb" … />. This separation of concerns enables useful functionality using Override form.