Wireless communication is the electromagnetic transfer of information between two or more points that are not connected by an electrical conductor. The most common wireless technologies use radio waves.Wireless communication networks offer transmission of signals, such as voice, data, and multimedia, without using wires, which is the crucial part of mobile communications. After successful deployment of wireless cellular networks in licensed bands and Wi-Fi networks in unlicensed bands, such as Industry, Scientific, and Medical (ISM) and Unlicensed National Information Infrastructure (UNII), over the last decade, several wireless networks, application, and services are emerging. Furthermore, wireless networks offer several advantages including mobility while getting service, scalability for further extension, reduced cost-of-ownership, and so on. However, there are some disadvantages and concerns, such as security, data rate, reliability, range, etc. The demand of ubiquitous communications is driving the development of wireless and mobile networks. Wireless communication is the fastest growing segment of the communication industry. This chapter provides the fundamentals of wireless and mobile networks and their advantages and disadvantages.Wireless communication networks offer transmission of signals, such as voice, data, and multimedia, without using wires, which is the crucial part of mobile communications. ... Wireless communication is the fastest growing segment of the communication industry