Surfing the Internet safely requires special care. While Apple tries to protect its systems as best it can, there are times when your connection is compromised, including when you connect to a public Wi-Fi network.
Broadly speaking, your Internet Service Provider (ISP) can see which websites you visit. If you trust your ISP, there are reasons to be careful when connecting to a public Wi-Fi network: a crook may attack. In the middle of man Monitor your connection.
What is a VPN?
This is where a virtual private network or VPN comes into play. This is like a tunnel that allows you to isolate the exchanges between your device and the server. This tunnel is generally encrypted, making it impossible to theoretically study your communications. On their part, visited sites do not see your home IP address, but the address of the VPN server.