How to display both the taxonomy parent and child in a node? I have a simple two-level taxonomy in my site: parent level is responsible for the "kind of place" (wine bar, restaurant...), and the children terms make more precise disintctions (french, italian etc. for restaurants).  

Now, if i display a taxononomy term, only the child appears (only "french", not "Restaurant French"). 

Is there any way to display both of them? I've found this http://drupal.org/node/1532198 
but I am not sure how to use it. 

Maybe there's a module that is more universal way, or a module that manages the display of the terms?
The answer you linked is correct. You need to write .tpl.php file and use provided code in place of default taxonomy renderer. In Drupal nodes belongs only to explicitly selected taxonomy element, not to it's parents. It was the design decision.