Job Control Language (JCL) is a scripting language used on IBM mainframe systems to instruct the operating system on how to execute batch jobs. It is a vital component in legacy systems, helping businesses automate tasks like data processing and reporting.

Key Components
Job Statements: Define the job's name, priority, and accounting information.
Exec Statements: Specify the program or utility to be executed.
DD Statements: Define data sources and destinations, such as input files, output files, or printers.
Why JCL Matters
Batch Processing: Efficiently processes large volumes of data in scheduled, automated workflows.
Resource Management: Allocates system resources like memory and CPU for each task.
Customizability: Allows fine-grained control over job execution parameters.
Despite its age, JCL remains relevant in industries like banking and insurance, where IBM mainframes are still in use for mission-critical applications.