A Data Set is a collection of information which is used in the form stream of bytes in logical record and block structures. Data Set is is firstly used by IBM mainframe operating systems. All the record of Data Set are in the form of organization, record format and other parameters. The physical structure of each record is almost same as Data Set records. Data Set can be organized into a splitter into another Data Set and there have multiple members that have another sub data. Data Set organization is similar to files being organized into directories or folders. PDSs are often used for executable programs and source program libraries. A PDS is analogous to a zip file in a file system, but the data is not compressed.