Nmap (Network Mapper) is an open-source network scanning tool used to discover hosts, identify open ports, detect running services, and gather detailed information about systems on a network.

1. • sT: The system call completes connections to open target ports rather than performing the half-open reset that SYN scan does.

1. -sU:

UDP scan works by sending a UDP packet to every targeted port

1. -sN:

(NULL scan) is an Nmap technique that sends TCP packets with no flags set to identify open or filtered ports based on target response behavior.

4. -sn:

-sn is used for host discovery only - it checks which systems are alive without performing any port scanning.

1. -v:

-v stands for verbose mode, which makes Nmap display more detailed output during the scan.