Enumeration involves actively interacting with the target's network to gather detailed and specific information. Identifying live hosts, services, and operating systems is a critical part of this process as it allows the penetration tester to map the network and identify potential points of entry. DNS lookups, while part of information gathering, do not provide detailed information about services or operating systems. War driving, which involves moving around an area to map wireless networks, doesn't focus on identifying live hosts, services, and operating systems in a target network directly.