AWS (Amazon Web Services) Certification Practice Exam

What defines a private subnet?

1. It has unrestricted internet access

2. It can communicate with the internet through a NAT Gateway

3. It cannot be accessed via the internet from the public

4. It is designed for hosting public-facing applications

The correct answer is: It cannot be accessed via the internet from the public

A private subnet is characterized by the inability to be accessed directly from the public internet. This definition is crucial for establishing network security and control over which resources can interact with the internet. By being isolated from direct internet access, private subnets typically house sensitive resources, such as databases and application servers, that do not need to be exposed publicly. The other options illustrate different characteristics that do not align with the principles of a private subnet. For instance, having unrestricted internet access contradicts the fundamental design of a private subnet, which is to limit such access for security reasons. Communicating with the internet through a NAT Gateway pertains to how resources in a private subnet can access the internet for outbound connections without exposing themselves to inbound traffic, but it does not mean that the subnet itself has public access. Finally, being designed for hosting public-facing applications directly contradicts the private subnet's primary purpose, which is to protect and manage critical assets without them being exposed to the broader internet.