Lord Zack's Planescape
The Elder Gods are a variety of beings older than the current gods. Some are yet worshiped, often by small, secretive cults, though some are worshiped alongside their younger kin. The Outer Gods are numbered among them as well as some of the Great Old Ones. There are also elemental deities that shaped the Material Plane when it was young (also known in some corners of the multiverse as Primordials). Some literally gave birth to the younger deities, other younger deities came later and merely supplanted them.