Sangam poems help us understand the social formation of the time. According to the Thinai concept, Tamilagam was divided into five landscapes or eco-regions, namely Kurinji, Marutham, Mullai, Neytal and Palai. Each region had distinct characteristics – a presiding deity, people and cultural life according to the environmental conditions, as follows:

– Kurinji: hilly region: hunting and gathering.

– Marutham: riverine tract: agriculture using plough and irrigation.

– Mullai: forested region: pastoralism combined with shifting cultivation

– Neythal: coastal land: fishing and salt making.

– Palai: parched land. Unsuitable for cultivation and hence people took to cattle lifting and robbery.