Crontab is a Unix-based utility that allows users to schedule and automate tasks on their systems. It enables users to run scripts or commands at specified intervals, such as daily, weekly, or monthly. This is particularly useful for routine maintenance tasks, backups, or any repetitive job that needs to be executed without manual intervention. Users can create and edit their crontab files using the command line, specifying the timing and the command to be executed. Each entry in a crontab file consists of time fields and the command, making it a powerful tool for system administrators and developers to manage tasks efficiently.