Definition
Packet capture, often abbreviated as PCAP, is the process of intercepting and logging network traffic that passes over a digital network or part of a network. It involves using specialized software or hardware to record the data packets in transit, allowing for later analysis. This technique is crucial for network troubleshooting, security monitoring, and performance analysis because it provides a detailed, unfiltered view of what is happening on the network. For instance, a network administrator might use packet capture to diagnose slow application performance by examining the sequence and content of data exchanged between clients and servers. Unlike network flow data which summarizes traffic, packet capture provides the raw, granular details of each individual packet. Understanding packet capture is essential for professionals preparing for certifications like CompTIA Security+, CySA+, and CISSP.