Virtual Private Cloud - Your own private section of AWS that's isolated from other users. Like having your own private neighborhood in a big city.
A bank creates a VPC to keep their financial applications separate and secure from other AWS users.
All provide private, logically isolated networking in the cloud (subnets, routing, security controls). AWS VPC and Azure VNet are regional constructs; Google Cloud VPC is global (subnets are regional); OCI VCN is regional.