Salam Dear Dhananjay,
Thank you for your question and for contacting Ask About Islam.
In fact, the term ‘Heaven’ - capitalized - has a shared meaning in Islam and all the other revealed religions. Primarily, it refers to that beautiful abode where, those who believe in only God, humble themselves to worship Him, do the good and avoid the evil, are promised to go after the end of this worldly life.
In this sense, it is the synonym of the "Gardens of Paradise", which is the equivalent of the Arabic word: Jannah. Those blessed dwellers will live there in an everlasting life.
This term, in Christian theology, may also mean a name of God the All Mighty. Again, in the sufist (mystic) tradition of both religions, this term means an ecstatic state of communion with God.
Thus, it is obvious that all the connotations of this word are spiritual and highly exalted, above the human level of worldly experience.
It is a transcendental space that the believers, though never experienced, yet are able to conceive through the detailed description that God has supplied them with. This is in order to arouse their incitement and longing for it. It is difficult to quote the many verses in Quran that describe Heaven, as these are so many!
It might be sufficient to know that every pleasure in that Heaven is unparalleled to that in the worldly life. It is as the prophet of Islam, Muhammad (peace be upon him), described to enclose:
"What no eye has ever seen and no ear has never heard and no human heart has ever perceived." (Narrated in the book of compiled hadiths by Imam Muslim)
Its food, houses, rivers, pleasures… everything is beyond imagination! And because the believer is always attached to the spiritual more than the sensual, even in Heaven, God has made the ultimate ecstasy for the believers there, is to look at His Holy Countenance. Such is a blessing, from which believers never get bored or even get accustomed to, despite familiarity.
Because this term – Heavens - refers to the place and condition of utmost happiness, it was borrowed or say, "hijacked", by those whose philosophy of life is a mere hedonistic one. I think that their choice of this word in particular is evidence, in itself, of their awareness of the model image of happiness and bliss.
But the gap is quite wide, between the model image and this worldly application of pleasure, which is definitely associated with a pain or discomfort of some kind, or at least with the sense of temporality or boredom. For this reason, those hedonists rely on a " carp diem" style of life. This is a Latin expression, which means: "live day by day". This would mean that you must exhaust your pleasure every day for fear that there may not be a second opportunity tomorrow!
If you need to know more about the description of Heaven, from the Islamic point of view, I recommend that you buy a CD of the Quran, the Muslim Holy book, and just search for the words "Heavens" and "Gardens of Paradise". Here, you will know much about the rewards that await the believers there and more important, the requirement for a believer to attain them. Such requirements would look simple compared to the reward, and can - with the mercy of God - be reached if one can persevere in obeying Allah and practicing true Islam.
Thank you again for your question and please keep in touch.
This Life and the Next
The Path to Jannah
Paradise: Safe and Sound