Which one of the elements automatically render all it's children in layout (m2)

Question

automatically render all it's children

<layout>
<container>
<block>
<action>

I feel like i've tried several now and they're not working for me. any of them. ugghhhh

Answer 1

Its container. < container >

Containers assign content structure to a page using container tags within a layout XML file. A container has no additional content except the content of included elements. Examples of containers include the header, left column, main column, and footer.