Windows Firewall is a software firewall, that you can use to block or allow different requests. In Windows 10 it is called Windows Defender Firewall.
Windows Firewall (officially called Microsoft Defender Firewall in Windows 10 version 2004 and later) is a firewall component of Microsoft Windows. It was first included in Windows XP SP2 and Windows Server 2003 SP1. Before the release of Windows XP Service Pack 2, it was known as the "Internet Connection Firewall."