The firewall is a filter that protects your PC, preventing unauthorized intruders from gaining access to it. It is also an effective tool for allowing you to use the Internet securely.
The firewall doesn't just filter inbound and outbound connections when the computer connects to the Internet, it also monitors connections between your computer and other network computers with which you can share files, folders, printers and other resources.
In most cases, the protection assigns connection permissions to each application automatically whenever possible, based on the risk level of the application and the communication direction (incoming/outgoing).
Exceptionally, however, depending on the application or the user that wants to establish the connection and the communication direction, the protection will ask you if you want to authorize the connection or not. It does this through pop-up messages that let you authorize or deny the connection and configure other related aspects.