Internet of Things technology is rapidly gaining popularity, not only in industrial and commercial environments, but also in personal life by means of smart devices at home. The Internet of Things (IoT) spawn new businesses and make buildings, cities and transport smarter. The IoT allows for ubiquitous data collection or tracking, but these useful features are also examples of privacy threats that are already limiting the success of the IoT vision when not implemented correctly. Privacy should be protected in the device, in storage, during communication, and at processing. The privacy of users and their data protection have been identified as one of the important challenges that need to be addressed in the IoT. The chapter presents the IoT technology, the various applications, and privacy issues. Various other issues such as security and performance are also addressed.