<type name="Magento\Customer\Block\SectionConfig">
    <arguments>
        <argument name="sectionConfig" xsi:type="object">
            SectionInvalidationConfigData
        </argument>
    </arguments>
</type>

This is a type configuration.

This configuration is for the base area. Base area configurations will apply to all the sub-applications.

This configuration tells the Object Manager that when a user wants a Magento\Customer\Block\SectionConfig object that the following arguments should be used in the foo object's constructor.

• $sectionConfig = new SectionInvalidationConfigData (...)

<type name="Magento\Customer\Block\SectionNamesProvider">
    <arguments>
        <argument name="sectionConfig" xsi:type="object">
            SectionInvalidationConfigData
        </argument>
    </arguments>
</type>

This is a type configuration.

This configuration is for the base area. Base area configurations will apply to all the sub-applications.

This configuration tells the Object Manager that when a user wants a Magento\Customer\Block\SectionNamesProvider object that the following arguments should be used in the foo object's constructor.

• $sectionConfig = new SectionInvalidationConfigData (...)

<virtualType name="SectionInvalidationConfigData"
             type="Magento\Framework\Config\Data">
    <arguments>
        <argument name="reader" xsi:type="object">
            SectionInvalidationConfigReader
        </argument>
        <argument name="cacheId" xsi:type="string">
            sections_invalidation_config
        </argument>
    </arguments>
</virtualType>

This is a virtual type configuration.

This configuration is for the base area. Base area configurations will apply to all the sub-applications.

This virtualType configuration tells the Object Manager when a user wants a virtual SectionInvalidationConfigData object that it should return a Magento\Framework\Config\Data object.

This configuration tells the Object Manager that when a user wants a SectionInvalidationConfigData object that the following arguments should be used in the foo object's constructor.

• $reader = new SectionInvalidationConfigReader (...)
• $cacheId = "sections_invalidation_config";