# Structured Storage Elements

Structured storage provides the equivalent of a complete file system for storing objects through the following elements:

- The IStorage, IStream, ILockBytes, and IRootStorage interfaces, along with a set of related interfaces &emdash; IPersistStorage, IPersist, IPersistFile, and IPersistStream.

- Helper APIs that facilitate your implementation of structured storage, as well as a second set of APIs for compound files, OLE’s implementation of the structured storage interfaces. OLE also provides a set of supporting structures and enumeration values used to organize parameters for interface methods and APIs.

- A set of access modes for regulating access to compound files.