A set-top box is a device that connects to a television and receives digital signals, allowing users to access various content such as cable TV, streaming services, and on-demand videos. It acts as a bridge between the TV and the internet or cable service, enabling features like recording shows and pausing live TV. These devices often come with remote controls and user-friendly interfaces, making it easy for viewers to navigate through channels and apps. Popular examples of set-top boxes include those from companies like Roku, Apple TV, and Amazon Fire TV.