The orbital occupied by the hydrogen electron is called a 1s orbital. The '1' represents the fact that the orbital is in the energy level closest to the nucleus.The 's' tells you about the shape of the orbital. S orbitals are spherical around the nucleus.
The 2S orbital is same as a 1S orbital except that the region where there is the greatest chance of finding the electron is further from the nucleus.This is the orbital at the second energy level.
The 3S orbital is further larger and has more probability of finding electrons.
1s orbitals are spherical whereas other orbitals are not. The 1s orbitals have no radial nodes but the other orbitals do. Energy is the most for 3s.