VPC

A custom VPC (Virtual Private Cloud) in Amazon Web Services (AWS) is a virtual network environment that you create and manage within AWS. It allows you to define your own network configuration, including IP address ranges, subnets, route tables, and network gateways.

When you create an AWS account, a default VPC is automatically provisioned for you. However, a custom VPC provides greater control and flexibility over your network architecture to meet your specific requirements.

With a custom VPC, you can:

Define IP address ranges: You can choose the IP address range for your VPC, known as the CIDR block, allowing you to segment your network and control IP address allocation.
Create subnets: Within your VPC, you can create multiple subnets, each residing in a different Availability Zone (AZ). Subnets enable you to partition your network and allocate resources, such as EC2 instances, to specific subnets.
Configure routing: You have control over the routing tables for your VPC, allowing you to define how traffic is routed within and outside of your VPC. You can set up custom routes and gateways to connect your VPC to the internet, other VPCs, or on-premises networks.
Implement network access controls: You can use security groups and network access control lists (ACLs) to control inbound and outbound traffic at the subnet and instance level, providing security for your resources.
Integrate with other AWS services: A custom VPC can be connected to other AWS services like Amazon S3, Amazon RDS, or Amazon EC2. You can control access and communication between your VPC and these services.

Custom VPCs provide isolation, security, and flexibility, allowing you to create a network environment tailored to your specific needs within the AWS cloud infrastructure.