On 7 April, 2020, the VPC service replaced the Private Networking service.
A Virtual Private Cloud (VPC) is a private network interface for collections of DigitalOcean resources. VPC networks provide a more secure connection between resources because the network is inaccessible from the public internet and other VPC networks. Traffic within a VPC network doesn’t count against bandwidth usage.
You can use VPC networks to organize and isolate resources into a more secure infrastructure for your applications, execution environments, and tenancies. VPC networks also give you more control over your infrastructure’s networking environment: you can select your network’s IP range, set up cloud firewalls, and configure internet gateways.
You can create a variety of new resources in a VPC network, but you can’t migrate all kinds of resources between networks.
You can check our official docs here: https://www.digitalocean.com/docs/networking/vpc/
If you do not require/need a private network you can simply provision your droplet. As you’ve mentioned this option is set to NO by default.
Hope that this helps!