Yes, the iPhone has a built-in VPN client, but it does not come with a built-in VPN service you can use for free. The iOS settings include a framework that allows you to manually configure a connection to a VPN network you already have access to, such as one provided by your employer or a personal VPN server you've set up yourself. You can find this under Settings > General > VPN & Device Management. However, to actually use a VPN, you typically need to sign up for a third-party service. The easiest way to use one is by downloading a dedicated VPN app from the App Store, which automatically configures these settings for you.