Modern systems use signal processing in anything from smaller, more power-efficient Internet of Things components to sophisticated sensor monitoring in automated cars and smart automated machines. This chapter focuses an overview of signal processing techniques and data collection related to sensors and sensors based applications. Effective analysis and handling of signals produced by sensors inside a system constitute a critical and crucial component of a well operating measurement or automatic systems. Depending on the applications, the raw signal obtained from the sensors is typically passes through few hardware circuits. The raw signals are processed through preamplifiers circuits for removing unwanted noise and providing strength of signals. In this chapter, various methods of data handling and signal processing methods will be described and discussed. Also includes the sensor systems in many fields of applications such as navigation, medical science, wearable devices for sports and health monitoring, and various IoT-based applications.