Yuga means a particular time cycle. God created different yuga based on what thoughts are prevalent at that particular period of time. There are 4 maha-yugas (major eras) that have periodic time cycles. In those maha-yugas, there are small yugas that also have different stages of purity affecting it. This is to give relief in kaliyug and create disharmony in satyug.
Maha-yugas
Satyug: Sat means pure. This time cycle has only purity. False intelligence is almost negligible and faults and vikaar (defects) are really not there. However to keep time cycle moving, there are small periods (maniyug) that are like kaliyug or dwapar yug that keep the small amount of impurity and that allows satyug to go on and creation to exist. Satyug is of the longest duration of all time cycles. It lasts for 3 million current years. Days are longer in satyug and each year is equivalent to 100 years of the current yuga. Individuals in Satyug were taller and lived longer (3000 years – 10,000 years of current yuga equivalent to 30 to 100 years of that yug). In satyug, there was only God, no duality.
Treta yug: Tret means Tri. A yuga that had 3 (not even duality). This was the yug of Shiv, Shakti and you. Here to attain moksh (salvation), one can to go through Shakti (energy), Shiv (who channelizes the energy) and you had to walk on that path. In Treta yug, people were pious, religious, righteous but could be drained to wrong track by emotions (e.g. King Dashrath, Queen Kaikeyi, Manthara etc). The average life span of individuals of treta yug was 400 – 1000 years of current yuga which is equivalent to 40 to 100 years of that yug. (1 year of treta yug is equivalent to 100 years of current yuga). Treta yug lasted for 1.5 million years of current yuga.
Dwapar yug: Dwapar means at the door. This is in between treta yug and kaliyug. Thus it is in between righteousness and injustice. Dwapar has a mixture of both treta yug and kaliyug. Mahabharat occured at end of dwapar yug and had both characteristic of treta (pandav) and kaliyug (kauravs). Dwapar yug lasts for 1 million years of current yuga. Each years of dwapar yug is equivalent to 5 years of kaliyug. Individuals lived for 200 to 400 years of current yuga.
Kaliyug: Kali means to destroy. The time cycle that only believes in destruction. Kaliyug has all the vikaar (defects) at its peak. Individuals have lost all their divine powers due to false intelligence. Kaliyug has injustice, violence, break-down of society, barbarism. There is no law and order. Kaliyug is the shortest yug. It lasts for 50,000 years. The average life span of individuals is only 60 years. In kaliyug, to achieve God is easiest as he is constantly watching over his children. He is giving his hand at the slightest effort. Intense effort of 10 years is enough to merge in God. Whereas in dwapar yug it requires at least 100 years, in treta yug 200 years and in satyug 1000 years.
- These are topics of various aspects of spirituality as told by Para.