OLE is an abbreviation for Object Linking and Embedding, which is essentially a proprietary technology invented by "Microsoft Corporation." OLE supports linking and embedding to all documents as well as many other objects that are known to be implemented on top of the so-called "Component Object Model" and OLE containers.
To export their functionality, the aforementioned objects can always implement the interfaces. There is just one mandatory interface - the "OleObject" interface — but all other interfaces may also need to be implemented if the functionality exposed by such interfaces is required at all. COM was a natural outgrowth of utilizing interfaces not merely to communicate data, but also to provide runtime functionality - where the data was backed up by actual code.