An electron in the Coulomb potential V = −e02/4πε0r created by a single proton. Solving the Schrödinger equation in polar coordinates gives ψ = Rnl(r)Ylm(θ,φ), from which 1s, 2s, 2p, 3s, 3p, 3d, … emerge. In ① you see the blurred electron itself, and in ② you see its shape.
All lengths are in units of the Bohr radius aB = 4πε0ħ2/mee02 = 52.918 pm.