What is SYN scan?

A SYN scan is a network scanning technique used to determine the status of ports on a target system. It sends SYN packets, which are part of the TCP handshake, to specified ports and analyzes the responses. If a port is open, the target will respond with a SYN-ACK packet; if it is closed, it will respond with a RST packet. This method is stealthy and less likely to be logged by intrusion detection systems compared to a full TCP connection scan.