GSM, or Global System for Mobile Communications, is a widely used standard for digital cellular communication. It represents a set of protocols and technologies that enable mobile devices, such as cell phones and tablets, to communicate with cellular networks and with each other.
GSM operates on various frequency bands and provides voice and data services, allowing users to make calls, send text messages, and access mobile internet services. GSM's key features include encryption for secure communication, efficient use of bandwidth through time-division multiplexing, and global compatibility, making it one of the most prevalent mobile communication standards worldwide.