Amazon Virtual Private Cloud (VPC) is an AWS service that enables the launch of AWS resources within a virtual network, providing high availability and security. To configure VPCs effectively, it's essential to choose the right CIDR block size, partitioning subnets into isolated segments for secure resource placement. Internet gateways and NAT gateways facilitate internet access, while route tables define traffic routing based on destination IP addresses. Virtual firewalls, including access control lists (ACLs) and security groups, can be used to fine-tune network traffic rules, controlling inbound and outbound traffic at the subnet level or specific resources within a VPC. By implementing these best practices, users can reduce their attack surface while ensuring application functionality and internet connectivity.