PCAP is a file format used by Wireshark, a network sniffer tool. Wireshark uses Libpcap or WinPcap network package capturing libraries for capturing and analysing network traffic.

PCAP files store captured data for further network traffic analysis. Wireshark is commonly used yb system or network administrators as well as by hackers or special service units. Wireshark is a free software available for various system platforms.