Explain how the periodic table is organized?

Explanation:
Periodic Table is based on periodic law which states that if elements are arranged in order of increasing atomic numbers then their properties are repeated in periodic manner. It is arranged in order of increasing atomic numbers. It has 2 groups.Group A elements are called normal or representative elements and group $\mathrm{B}$ elements are called transition elements. It has four blocks s,p,d,f.
First 3 periods are called short periods and remaining periods are called long periods.Elements with similar valence shell electronic configuration are placed in same group one below other.
elements of a group have same chemical properties.