calling a named template - this is an imperative approach which should be avoided.
by activating a template by selecting elements (or other nodes) and letting the processor to find a matching template itself - functional approach - preferable.
The selection of nodes is done by:
Explicitly by "select" at "apply-templates". We can select any nodes specified by the XPath expression in "select".
Implicitly, letting the processor to select nodes (no "select" at "apply-templates"). Only child elements are selected then.