Which library is primarily used for packet capture on Windows?

• A. Libpcap
• B. WinPcap
• C. Npcap
• D. PcapNG

Answer: (B)

Think about how programs on Windows access network traffic. They need a library that talks to the Windows capture driver and exposes a consistent API to grab packets in real time. WinPcap is the Windows port of the cross-platform libpcap, and for a long time it provided the essential capture driver and API used by many Windows sniffing tools (like Wireshark) to open interfaces, apply filters, capture packets, and even inject traffic. That historical role makes it the typical answer for Windows packet capture. It’s worth noting that WinPcap has been superseded by Npcap, which offers similar functionality with improved performance and Windows compatibility, but the classic, widely-supported Windows capture library relied on by many tools has been WinPcap. Libpcap is the Unix/Linux version, and PcapNG is a file format for saved traffic, not a capture library.