How does COBOL handle files?

COBOL uses FILE SECTION in DATA DIVISION.

• Files are processed using OPEN, READ, WRITE, CLOSE.

Example:

IDENTIFICATION DIVISION.
PROGRAM-ID. FILE-DEMO.

ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT EMP-FILE ASSIGN TO 'EMP.DAT'
ORGANIZATION IS LINE SEQUENTIAL.
DATA DIVISION.
FILE SECTION.
FD EMP-FILE.
01 EMP-REC.
   05 EMP-ID     PIC 9(4).
   05 EMP-NAME   PIC A(20).

WORKING-STORAGE SECTION.
01 WS-EOF PIC X VALUE 'N'.

PROCEDURE DIVISION.
OPEN INPUT EMP-FILE
PERFORM UNTIL WS-EOF = 'Y'
    READ EMP-FILE
        AT END MOVE 'Y' TO WS-EOF
        NOT AT END DISPLAY EMP-REC
    END-READ
END-PERFORM
CLOSE EMP-FILE
STOP RUN.