To identify a botnet, one must first identify the source of its attacks. In most situations, these are computers and IoT devices like IP cameras and home WiFi routers. Still, people can manipulate these gadgets even though they get infected with malware. A Botnet has all of these devices.
A hacker creates a botnet to take advantage of a flaw in a system and turns it into a botmaster. The botmaster looks for other computers that are susceptible and infects them with malware. When a sufficient number of devices have gotten infected, the hacker instructs them to launch an attack; each machine sends a torrent of requests to the target server or network, overloading it and causing slowdowns or failure.