What were the four social divisions in Sangam society as mentioned in Tolkappiyam?

Why are the cities of Puhar and Madurai significant in Sangam literature?

What emblem did the Pandyas use, and what did it symbolise?

Read the following excerpt and answer the questions that follow:

"Tolkappiyam, a treatise on Tamil grammar and poetics, composed probably during the second Sangam, is the oldest extant literary work in Tamil."

(Source: https://www.du.ac.in/up/oads/new-web/04012023_Appendix-108.pdf)

(a) What is the significance of the grammatical treatise Tolkappiyam?

(b) Why is Tolkappiyam important for understanding Tamil society?