Nibbana
Nibbana is the final goal of Buddhism. What is Nibbana then? It is not easy to know what Nibbana really is; it is easier to know what Nibbana is not. Nibbana is not nothingness or extinction. Would the Buddha leave His family and kingdom and preach for 45 years - all for nothingness?
Nibbana is not a paradise. Several centuries after the Buddha, some of the Buddhist sects began to introduce Nibbana as a paradise. Their purpose of equating Nibbana with a heavenly world was to convince the 'less-intellectually-gifted' and to attract them to the teachings of the sect. Striving for Nibbana came to mean looking for a nice place where everything is beautiful and where everyone is eternally happy. This might be a very comfortable folktale, but it is not the Nibbana that the Buddha experienced and introduced.
If Nibbana is not a place, where is Nibbana then? Nibbana exists just as fire exists. However, there is no storage place for fire or for Nibbana. But when you rub pieces of wood together, then the friction and heat are the proper conditions for fire to arise. Likewise, when the nature in man's mind is such that he is free from all defilements, then Nibbanic bliss will appear.
By itself, Nibbana is quite unexplainable and quite undefinable. As darkness can only be explained only by its opposite, light, and as calm can only be explained by its opposite, motion, so likewise Nibbana, as a state equated to the extinction of all suffering can be explained by its opposite - the suffering that is being endured in Samsara. As darkness prevails wherever there is no light, as calm prevails wherever there is no motion, so likewise Nibbana is everywhere where suffering and change and impurity do not prevail.
A sufferer who scratches his sores can experience a temporary relief. This temporary relief will aggravate the wounds and cause the disease to be enhanced. The joy of the final cure can hardly be compared to the fleeting relief obtained from the scratching. Likewise, satisfying the craving for sense-desires brings only temporary gratification or happiness which prolongs the stay in Samsara. The cure for samsaric disease is Nibbana. Nibbana is an end of the cravings which cause all the sufferings of birth, old age, disease, death, grief, lamentation and despair. The joy of Nibbanic cure can hardly be compared to the temporary Samsaric pleasure gained through fulfilling the sense desires.
It is dangerous to speculate on what Nibbana is; it is better to know how to prepare the conditions necessary for Nibbana, how to attain the inner peace and clarity of vision that leads to Nibbana. Follow the Buddha's advice: put His Teachings into practice. Get rid of all your defilements which are rooted in greed, hatred, and delusion. Purify yourself of all desires and realize absolute selflessness. Lead a life of right moral conduct and constantly practise meditation. By active exertion, free yourself from all selfishness and illusion. Then, Nibbana is gained and experienced.
Source: What Buddhists Believe by Venerable Dr. K. Sri. Dhammananda