This chapter introduces the enabling technologies behind cochlear implants. It begins with a retrospective overview of the key technological contributions that have significantly influenced the architectural design of current cochlear implant systems. To support this, a comprehensive literature review and a series of interviews were conducted. Readers are encouraged to consult the recommended bibliography for a deeper understanding of the history of cochlear implants. Following this historical context, the chapter presents fundamental principles of electrical stimulation in cochlear implants. This includes a brief overview of various configurations and stimulation parameters, and how these affect the auditory nerve. Building on this foundation, the current architecture of most cochlear implants is examined, analyzed through the lens of different user subsystems—namely, the patient, clinician, surgeon, and audiologist. The chapter concludes with a forward-looking discussion on how cochlear implant technologies may evolve in the coming years.