A Virtual Private Cloud (VPC) in Google Cloud Platform (GCP) is a secure and isolated environment within the public cloud. It allows users to deploy and manage virtual machines (VMs) and applications in a private network setting, offering an added layer of security through customizable network configurations like IP ranges, subnets, and firewall rules.

Key Features of GCP VPC:

1. Security and Isolation: A GPC VPC ensures that your resources are separate from other users and shielded from unauthorized access, providing a dedicated environment for your applications and workloads.
2. Connectivity Options: It offers secure connectivity options between on-premises infrastructure and GCP resources. This is achieved through VPN tunnels or dedicated interconnects, allowing seamless integration and secure data transfer.
3. Networking Capabilities: Advanced features like network peering for connecting VPCs within the same or different projects and load balancing for even traffic distribution are available.
4. Robust Security Features: Includes DDoS protection to defend against malicious attacks and customizable firewall rules for controlling inbound and outbound traffic.

Creating VPC Networks and Subnets:

• Auto Mode vs. Custom Mode: In auto mode, subnets are automatically created in each region with predefined IP ranges. Custom mode, on the other hand, allows for more control over subnet creation and IP range definition, suited better for production environments.
• Subnet Creation: For an auto mode VPC network, subnets are automatically created in each region using predefined IP ranges. In contrast, a custom mode VPC network starts with no subnets, offering complete control over their creation.

Usage Scenarios:

• Auto mode VPC networks are simpler to deploy but offer less control, making them suitable for basic or non-production environments.
• Custom mode VPC networks provide flexibility and are recommended for production environments, especially when connecting multiple VPC networks through VPC Network Peering.

Overall, a VPC in GCP offers a powerful combination of security, scalability, networking capabilities, and integration options, making it an ideal choice for organizations seeking to manage their cloud environments securely and efficiently.

For more detailed information on GCP VPC, you can refer to DataScientest, Cloud Academy, and Cloud Defense.