In the present era, the requirement of machine to machine communication is increasing very rapidly. Internet of Things (IoT) is creating abundant opportunities in business, government, education, and health. IoT is gaining popularity in many other areas too with the reduction in cost of smart computing technologies. Now building a network of all kinds of devices and objects has become possible after emergence of sensors, actuators, transducers, and embedded system. Data flows through various entities using wireless sensor networks and IoT systems. The entire machine to machine (M2M) communication interface can use any communication protocol (such as Bluetooth, 3G, 4G, Z-Wave, Wi-Fi, NFC, LTE, Ethernet, LoRaWAN, Radio, Cellular, and etc.). Objects can be sensed and controlled across any network infrastructure in digital environment using IoT technology. Physical world is being integrated into computer based digital systems resulting which the benefit of less human intervention. Now human is living into cyber-physical world where performed operations are more accurate, efficient and economic. Connected devices used in different environments present many opportunities as well as risks in front of cyber-physical world. These risks or incidents could be identified using digital forensics investigation technology. Hence, digital forensics must be properly explored for solving various malicious problems of IoT. This paper presents a survey of the need of digital forensics in ongoing IoT applications. Various threats faced by IoT enabled smart environment also have been discussed in the present paper. Paper also highlights some applications, characteristics, and application criteria of IoT in digital domain. The main objective of this paper is to present general process phases of digital forensics. One more motive of this paper is to identify and explore various reasons to deploy digital forensics in IoT enabled smart environment in different application domains.