Hi Harridu,
MacOS includes two different types of firewall: an application-based firewall and a packet-filter firewall. The application-based firewall, also known as the application layer firewall, controls incoming and outgoing network traffic based on the specific rules that you set for each installed application. This type of firewall is typically used to prevent unauthorized access to your computer and to limit the types of incoming and outgoing network traffic that specific applications are allowed to handle.
What is the network-layer firewall?
The packet-filter firewall, also known as the network layer firewall, controls incoming and outgoing network traffic based on pre-defined rules that specify which types of network packets are allowed to pass through the firewall and which ones are blocked. This type of firewall is typically used to protect your computer from external threats, such as malicious network traffic or unauthorized access attempts.
What is an application-based firewall?
An application-based firewall, also known as an application layer firewall, is a type of firewall that controls incoming and outgoing network traffic based on the specific rules that you set for each installed application. This type of firewall is typically used to prevent unauthorized access to your computer and to limit the types of incoming and outgoing network traffic that specific applications are allowed to handle.
An application-based firewall works by inspecting the data that is being sent and received by each installed application and only allowing network traffic that matches the specific rules that you have set for that application. This allows you to have fine-grained control over the types of network traffic that each application is allowed to handle, which can help to prevent unauthorized access to your computer and protect against potential security threats.
In general, traffic has to pass through both the application-based firewall and the packet-filter firewall in order to reach its destination. The packet-filter firewall is typically used first, as it is responsible for controlling the flow of network traffic at a lower level than the application-based firewall.