Sensors have become ubiquitous in the daily life of humans and are used in various use cases, ranging from smart home assistants to smartphones and fitness trackers. In all these applications, information such as sound, vision, health status, etc. is transformed from an initial analog signal into digital data, which can be processed by algorithms, leading to insights and/or actions. In this introductory chapter, the position of sensors in today’s global IT and electronic infrastructure and their challenges will be sketched, and some background regarding sensors and their electronic interfaces will be given.