This paper provides an overview of augmented reality (AR) technologies, applications, and limitations. AR is a technology that enhances the real world with virtual elements, allowing users to see, hear, and feel their environments in new and enriched ways. It has potential applications in various fields, including education, maintenance, design, and reconnaissance. The paper discusses the development history of AR, its enabling technologies, and the current state of the art. It also reviews some recent applications of AR technology and highlights some known limitations regarding human factors in the use of AR systems. AR is classified as a part of mixed reality, and it differs from virtual reality (VR) and telepresence in that it provides local virtuality. AR systems combine real and virtual objects in a real environment, register them with each other, and run interactively in three dimensions and in real time. The paper discusses the key components needed to build an AR system, including display technologies, tracking sensors, and user interface technologies. It also covers the challenges and limitations of AR, such as the need for accurate tracking, the impact of human factors, and the need for computational frameworks, wireless networking, and data storage and access technology. The paper also discusses the applications of AR in various fields, including personal information systems, navigation, touring, industrial and military applications, and more. It highlights the potential of AR in creating situated documentaries, reconstructing cultural heritage sites, and assisting in design, assembly, and maintenance tasks. The paper concludes with a discussion of the future directions of AR research, including the development of more advanced AR systems and the integration of AR with other technologies.This paper provides an overview of augmented reality (AR) technologies, applications, and limitations. AR is a technology that enhances the real world with virtual elements, allowing users to see, hear, and feel their environments in new and enriched ways. It has potential applications in various fields, including education, maintenance, design, and reconnaissance. The paper discusses the development history of AR, its enabling technologies, and the current state of the art. It also reviews some recent applications of AR technology and highlights some known limitations regarding human factors in the use of AR systems. AR is classified as a part of mixed reality, and it differs from virtual reality (VR) and telepresence in that it provides local virtuality. AR systems combine real and virtual objects in a real environment, register them with each other, and run interactively in three dimensions and in real time. The paper discusses the key components needed to build an AR system, including display technologies, tracking sensors, and user interface technologies. It also covers the challenges and limitations of AR, such as the need for accurate tracking, the impact of human factors, and the need for computational frameworks, wireless networking, and data storage and access technology. The paper also discusses the applications of AR in various fields, including personal information systems, navigation, touring, industrial and military applications, and more. It highlights the potential of AR in creating situated documentaries, reconstructing cultural heritage sites, and assisting in design, assembly, and maintenance tasks. The paper concludes with a discussion of the future directions of AR research, including the development of more advanced AR systems and the integration of AR with other technologies.