This chapter examines the ever-changing field of surveillance systems, covering everything from their core technology to upcoming advancements. Surveillance, which was formerly dependent on basic recording equipment, has changed as a result of innovations like artificial intelligence (AI), the Internet of Things (IoT), and closed-circuit television (CCTV). While these technologies improve real-time data processing and prediction capacities, they also present difficult privacy and ethical issues. The chapter examines the fundamental technologies of contemporary surveillance, such as cloud computing for scalable data storage, IoT for integrated monitoring, and AI for behavior analysis. In addition, it looks at moral and legal issues including protecting privacy and striking a balance between security and civil freedoms. Future developments in technology, such as augmented reality and quantum computing, have great potential for progress.