The world of wireless communication is moving quickly toward the sixth generation (6G), which is expected to bring much more powerful features than today's 5G networks. While 5G supports fast internet, reliable connections, and massive use of smart devices, the growing demand for intelligent applications needs even better solutions. 6G will make use of new technologies such as terahertz (THz) communication, reconfigurable intelligent surfaces (RIS), visible light communication (VLC), integrated sensing with communication (ISAC), and artificial intelligence (AI)-based networking. These will enable advanced applications like holographic communication, digital twins, extended reality (XR), smart healthcare, self-driving systems, and global space-air-ground networks. However, there are still many open challenges, including limited spectrum, high energy use, hardware cost, security, privacy, and lack of standards. This paper gives a clear overview of the main technologies, possible applications, and open issues of 6G communication and will help researchers and engineers to understand future directions in this field.