Degenerate orbitals are orbitals with the same energy.
Ideally, this would mean that all the orbitals with the same principal quantum number (
However, this does not happen because of electron shielding (i.e. inner electrons repel outer electrons), which causes more outer orbitals to have higher energy.
To sum up, a good rule of thumb to keep in mind is that all orbitals with the same principle quantum number (
Hope that helps :)