Why Are The Blocks In Modern Periodic Table Named "S-block ","P-block, "d-block ","f-block"?

There are four sub-orbits or orbitals in an atom including s, p, d and f. The maximum number of electrons that s, p, d and f orbitals can posses are 2, 6, 10 and 14. A periodic table is an arrangement of elements according to the ascending order of the atomic number of elements. Periodic table is divided into four blocks that are s block, p block, d block and f block. The elements with valance electrons in s-orbitals are placed in s-block, the elements in which valence electrons are present in p-orbital are placed in p-block. Similarly, elements with valence electrons in d and f orbitals are categorized as d-block and f-block elements respectively.