Internet of things (IoT) has emerged as one of the most influential trends during the past few years, with many solutions in various domains. Many funds and studies have been focused on IoT technologies as well. Most of the studies on IoT have focused on technologies in a particular related area. To the best of our knowledge, a study covering various aspects of IoT technology has not been reported. In this research, based on the related published standards, reported studies in the literature, and proposed architectures and solutions from leading companies, we propose a technology tree for IoT that covers all the related technology areas in enough details using a top-down approach. The proposed technology tree could be used in studies that need to have a comprehensive overview of IoT-related technologies, including both technological and non-technological points of view such as economic study and futurology. The proposed tree could be more refined to meet enough details if necessary.