Wrapping is the process of hiding PL/SQL source code. Wrapping helps to protect your source code from business competitors and others who might misuse it.
You can wrap PL/SQL source code with either the wrap utility or DBMS_DDL subprograms. The wrap utility wraps a single source file, such as a SQL*Plus script. The DBMS_DDL subprograms wrap a single dynamically generated PL/SQL unit, such as a single CREATE PROCEDURE statement.
http://docs.oracle.com/cd/B28359_01/appdev.111/b28370/wrap.htm