The technology is seeing a rapid growth day by day in the life of humans. Rapid growth intechnology has led to newer inventions that has made human lives very comfortable. The introduction of Internet Of Things (IOT) has brought a drastic change in the way humans lead their lives. Network plays an important role in each and every technology as it allows connection and communication between different objects and entities of any application. Different models like OSI, TCP demonstrate how computer system communicate over a network. Each of these models have different layers in it. This paper mainly focuses on the application layer which enables effective communication with other applications on different computer systems and different networks. Also the paper discuss different application layer IoT based protocols that work in the application layer by considering the scenario of Smart Home to demonstrate working of each protocol.