A botnet is a network of computers that have been infected with malicious software, allowing a hacker to control them remotely. These infected machines, often called bots or zombies, can be used to perform various tasks without the owner's knowledge, such as sending spam emails or launching attacks on websites. Botnets can be very powerful, as they can consist of thousands or even millions of infected devices. This makes them a significant threat in the world of cybersecurity, as they can disrupt services and steal sensitive information. Protecting devices from becoming part of a botnet is crucial for maintaining online safety.