The `poll()` function is a system call used in programming, particularly in the context of operating systems like Linux. It allows a program to monitor multiple file descriptors to see if they are ready for reading or writing. This is useful for managing input/output operations without blocking the program's execution. When a program calls `poll()`, it provides a list of file descriptors and specifies the events it is interested in, such as data availability. The function then waits until one or more of these descriptors are ready, allowing the program to respond efficiently to user input or network activity without wasting resources.