Shell scripts are text files that contain a series of commands for a computer's operating system to execute. They are typically written for command-line interfaces like Bash in Linux or macOS, allowing users to automate repetitive tasks, manage system operations, and streamline workflows. By using shell scripts, users can save time and reduce the risk of errors in manual command entry. These scripts can include various programming constructs such as loops, conditionals, and functions, making them versatile for different applications. Shell scripts are commonly used for tasks like file manipulation, program execution, and system monitoring, making them essential tools for system administrators and developers.