Final answer:
The VCN component that blocks inbound but permits outbound traffic is a stateful firewall, such as security groups or NSGs in common cloud platforms.
Step-by-step explanation:
The virtual cloud network (VCN) component that blocks inbound traffic but allows outbound traffic to the internet is commonly known as a stateful firewall. A stateful firewall can be configured to restrict incoming requests to protect the network from unauthorized access while permitting outgoing communications. This is often necessary for applications and services that require internet access for updates and external data while maintaining a secure environment against inbound threats.
In the context of cloud computing, providers may have specific terms for these components, such as security groups or network access control lists (NACLs) in Amazon Web Services (AWS) or network security groups (NSGs) in Microsoft Azure.