What exactly does tapas (austerity) involve?

Ans : Tapas actually means blazing, burning and conveys the meaning of something fiery or filled with intense heat. Tapas or fieriness-what exactly does it infer? Fire is the most wonderful purifying agent in the world, and it illumines, so these two aspects you must keep in mind. So tapas is an intense process that burns up impurities in the nature of man and fills him with the radiance and purity of spiritual consciousness. It is purification and illumination of a person's personality, and anything done towards this end can legitimately be called tapas. So tapas may vary from individual to individual, but there are certain universal weaknesses common to all. Everyone likes to take a lot of food, so fasting is a universal method of self-control. The sex-impulse is also a universal passion; therefore a rigid vow of chastity would be a severe kind of tapas. Trying to control impure sentiments and feelings of the mind is also great tapas. It purifies the nature as nothing else can do. But it may be that the greatest tapas is sticking to the truth. If a man sticks to the truth, he will know what trials and tribulations it takes him through. But all in all this is meant to say that anything that brings you nearer to the truth is a tapas, and it may take any form.