The degenerate orbitals with the same quantum numbers are those found in the same region of energy levels as well as symmetry.
Degenerate orbitals are generated when a single orbital holds two electrons with different spins, or one electron of each spin. For example, up and down spins can combine together to form an orbit between them if there is only enough room on one ‘line’ for these two electrons. When they collide this way, their coefficient becomes a half-integer value such as 1/2 or 3/2 instead of what would usually be expected – 1. If this was to happen in every instance which might have occurred prior to their collision – that is, if there had been 2 more space on either side in which to put 2 more up or down spins – then each level would have in principle been able to accommodate 8 electrons in pairs. No further degenerate orbitals would arise.
However, if the collision of two electrons does not form a degenerate orbital – it is said to be non-degenerate and the original orbitals remain as they are. For example, if both spins were up/up or down/down, then no new orbital is formed, and this new ‘level’ of energy only has the electron configuration 1s.