The Internet of Things (IoT) is a hot topic these days, empowers everyday devices with identification and communication capabilities, spanning diverse domains like smart appliances, smart cities, wearables, and Electronic-health data. This expansive connectivity is anticipated to link tens to hundreds of billions of devices, each equipped with smart functionalities for autonomous data collection, analysis, and decision-making. Both academia and industry are determined to make progress in improving usability, maintainability, and security by establishing standards and best practices. Security is particularly important because it currently poses a major obstacle to wider adoption of the Internet of Things. There are various areas of research in the security field, including cryptography, network security, and identity management. In this paper, we focus on the application layer of the IoT environment, specifically in the areas of authentication, and authorization. This survey conducts an extensive comparative examination of contemporary IoT authorization and Authentication schemes, aiming to illuminate both their strengths and weaknesses. It subsequently delineates crucial requirements, elucidates authorization threats, and underscores weaknesses affecting IoT authorization. The survey concludes by outlining persisting open challenges in authorization and offering recommendations for prospective research.