Do subnets in a VPC need to be either public or private?

Subnets within a Virtual Private Cloud (VPC) indeed fall into two primary categories: public and private. A public subnet is one that has a route to an Internet Gateway, allowing resources within the subnet to communicate directly with the internet. Conversely, a private subnet does not have such direct access to the internet; instead, resources within it may communicate with the internet via a Network Address Translation (NAT) gateway or instance.

By categorizing subnets into public or private, it helps define the level of accessibility and the type of resources that can be deployed within them. This categorization is essential for implementing security measures, controlling data flow, and maintaining an organized network structure. Properly distinguishing between the two types of subnets allows for more effective architecture of a VPC, tailored to specific application needs and security compliance.

The other options suggest various extremes regarding subnet classification, which do not accurately reflect the flexible and purposeful design of VPC networks. Thus, the correct understanding that subnets must be categorized into public or private is fundamental to managing a VPC effectively.