IFS
From MidrangeWiki
The Integrated File System, or IFS, is a heirarchial file system available on the iSeries that is very similar to a unix file system.
The IFS can be accessed from the green screen using a standard command interface, the Qshell command line, iSeries Navigator, and Windows networking shares through Netserver support.
Java applications are stored in, and executed from, the IFS.