System Firewall helps you keep your computer more secure against intruders and malicious network traffic by restricting the information that reaches your computer from other computers by having more control over the data that reaches your machine and giving you a defensive line against hackers, malicious programs - Viruses, worms, Trojans, keylogers - trying to connect to your computer without invitation.
Think of a firewall as a barrier that checks information that comes from the internet or from the local network, whether or not it allows it to reach your computer depending on how you have configured your firewall.
You can free download System Firewall 32, 64 bit and safe install the latest trial or new full version for Windows 10 from the official site.