MANET is a type of mobile ad hoc network that allows devices to connect to each other without a centralized infrastructure. It consists of independent mobile nodes that form a temporary network without any established routers. MANETs are highly flexible and robust as they have a fully distributed network architecture. They can be used in military operations, disaster relief efforts, and business meetings where a wireless temporary network is needed. However, MANETs are more vulnerable to security attacks than wired networks due to their changing topology and lack of centralized monitoring.