parent element; containing element
Computing term for an element that contains or encloses other elements, such as in XML/HTML or data structures.
このXMLでは、ブック要素が親要素で、タイトル要素が子要素です。
In this XML, the book element is the parent element and the title element is the child element.
Compound of 親 (oya, 'parent') and 要素 (yōso, 'element'). A straightforward technical term.