<type name="Magento\Vault\Model\Method\Vault">
    <arguments>
        <argument name="config" xsi:type="object">
            Magento\Payment\Gateway\Config\Config
        </argument>
        <argument name="valueHandlerPool" xsi:type="object">
            VaultPaymentValueHandlerPool
        </argument>
        <argument name="vaultProvider" xsi:type="object">
            Magento\Vault\Model\Method\NullPaymentProvider
        </argument>
        <argument name="code" xsi:type="string">
            vault
        </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\Vault\Model\Method\Vault object that the following arguments should be used in the foo object's constructor.

• $config = new Magento\Payment\Gateway\Config\Config (...)
• $valueHandlerPool = new VaultPaymentValueHandlerPool (...)
• $vaultProvider = new Magento\Vault\Model\Method\NullPaymentProvider (...)
• $code = "vault";