<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 (...)