The standard ambient font property supplied by the container and the standard font property supplied by the control both provide a standard font object. That is, these standard fonts supply an IDispatch pointer to a standard font object.
The font object is a system-provided implementation of a set of interfaces on top of the underlying GDI font support. A font object is created through the API function OleCreateFontIndirect given a FONTDESC structure. The font object supports a number of read-write properties as well as custom methods through its interface IFont, and supports the same set of properties (but not the methods) through a dispinterface IFontDisp. The dispinterface is used for the font properties mentioned previously. The properties correspond to the GDI font attributes that are described in the LOGFONT structure.
The font object also supports the outgoing interface IPropertyNotifySink so that a client can determine when font properties change. Since the font object supports at least one outgoing interface, it also implements IConnectionPointContainer and one connection point for IPropertyNotifySink for this purpose.
The font object provides an hFont property that is a Windows font handle that conforms to the other attributes specified for the font. The font object delays realizing this GDI hFont when possible, so consecutively setting two properties on a font won't cause an intermediate font to be realized. In addition, as an optimization, the standard font object maintains a cache of font handles. Two font objects in the same process that have identical properties will return the same font handle. The font object can remove fonts from this cache at will, which introduces special considerations for clients using this hFont property. See IFont::get_hFont for more details.
The font object also supports IPersistStream such that it can save and load itself from an instance of IStream. Any other object that uses a font object internally would normally save and load the font as part of the object's own persistence handling.
In addition, the font object supports IDataObject through which it provides a property set containing typed values for each font property.