**What is Firewall?**\
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A firewall is a network security system, either hardware- or software-based, that controls incoming and outgoing network traffic based on predetermined security rules. In the context of Google Cloud Platform (GCP), firewall rules define the allowed connections to and from VM instances, providing a layer of protection by filtering traffic based on IP addresses, protocols, and ports. This helps prevent unauthorized access and ensures network security within GCP environments.\
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**What is the Allow HTTP Traffic option?**\
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The "Allow HTTP Traffic" option in Google Cloud Platform (GCP) refers to a firewall rule set that permits incoming HTTP (Hypertext Transfer Protocol) traffic to specified resources, typically virtual machine instances. Enabling this option allows these instances to receive and respond to HTTP requests, facilitating web server functionality and web application hosting within GCP environments.