Zend certified PHP/Magento developer

Difference between various default.xml

I’m trying to do some simple modify to my theme, but I can’t understand why there are 2 differente default.xml, one under vendormagentomodule-themeviewfrontendlayout and the other under vendormagentotheme-frontend-lumaMagento_Themelayout

If I add my default.xml under appdesignfrontendvendorthemeMagento_Themelayout and the header.links block disappear.

This is my last try after dozen of it

<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">

<body>

<move element="top.search" destination="head.col.left" after="store_language" />
<move element="logo" destination="head.col.center" />
<move element="minicart" destination="head.col.right" />
<move element="header.panel" as="header.panel.new" destination="header.panel.wrapper" />
<move element="header.links" destination="header.panel.new" />

<referenceContainer name="top.head">
<container name="header.navi" label="Page Header Navigation top" htmlTag="div" htmlClass="container-xxl">
    <block class="MagentoFrameworkViewElementTemplate" name="head.top" template="Magento_Theme::html/head-top.phtml"></block>
</container>
</referenceContainer>
  
<referenceContainer name="header.container">
    <container name="header.panel.wrapper" htmlClass="middle_head" htmlTag="div" before="-">
        <container name="header.panel.new" label="Page Header Panel" htmlTag="div" htmlClass="container-xxl panel wrapper">
            <container name="middle.head.row" htmlClass="row panel header" htmlTag="div">
            
                <container name="head.col.left" htmlClass="col-4 uno" htmlTag="div" after="middle.head.row">
                    <block class="MagentoFrameworkViewElementTemplate" name="skip_to_content" template="Magento_Theme::html/skip.phtml">
                        <arguments>
                            <argument name="target" xsi:type="string">contentarea</argument>
                            <argument name="label" translate="true" xsi:type="string">Skip to Content</argument>
                        </arguments>
                    </block>
                    <block class="MagentoStoreBlockSwitcher" name="store_language" as="store_language" template="Magento_Store::switch/languages.phtml">
                        <arguments>
                            <argument name="view_model" xsi:type="object">MagentoStoreViewModelSwitcherUrlProvider</argument>
                        </arguments>
                    </block>
                </container>
                
                <container name="head.col.center" htmlClass="col-4 due" htmlTag="div" after="head.col.left">

                </container>
                
                <container name="head.col.right" htmlClass="col-4 tre" htmlTag="div" after="head.col.center">

                </container>

            </container>
        </container>
    </container>    

</referenceContainer>  
  
</body>
</page>