COPYLIB is a private library specifies that where the copy books are available. COPYLIB libraries are of type PDS. Each member in the PDS is a user written COBOL source code which is a part of actual program.

COPYLIB can be used to search the copy books used in the library during the compilation of the program.

A COPY statement can copies the source code from library to program. COPYLIB can be coded during the compilation time and along with compilation step.

//COPYLIB DD DSN=copybook-library

If the COPY control statement used enter the COPYLIB DD statement. The COPYLIB DD statement contains control statement members selected by COPY control statement.