A modem is a device that enables communication between a computer and the internet by converting digital signals from the computer into analog signals that can be transmitted over telephone lines or other communication channels. It acts as a bridge between the computer and the internet, allowing data to be transmitted and received, ultimately providing a connection to the online world. The symbols 📶💻 represent the wireless signal and computer, highlighting the modem's role in facilitating connectivity and bridging the gap between devices and the internet.