So what does Carpe Diem means?

Got this phrase from one of Robin Williams movie.."Dead Poet Society".

http://en.wikipedia.org/wiki/Carpe_diem
Carpe diem is a phrase from a Latin poem by Horace (Odes 1.11). It is popularly translated to "seize the day", however, the most appropriate translation, considering the meaning of "carpe" in the sentence as a whole, is believed to be "gather the day", as in picking or plucking a fruit.

One interpretation of the phrase might be as an existential cautionary term, much like "eat, drink and be merry, for tomorrow we die" with emphasis on making the most of current opportunities because life is short and time is fleeting. It has, therefore, some connections with another Latin phrase, Memento mori.

The phrase is often extended to explicitly mention the possibility of imminent death, as in "Seize the day, for tomorrow you may die."

Along the same theme, and evoking some of the same imagery as the poem, is the expression "Eat, drink, and be merry, for tomorrow we die", which derives from Biblical verses (such as Isaiah 22:13), and which occurs many times in modern English-language popular culture.

Related but distinct is the expression memento mori, "remember that you are mortal"; indeed, memento mori is often used with some of the sense of carpe diem. However, two major elements of memento mori are humility and repentance, neither of which figures prominently in the concept of carpe diem.

Carpe Diem! Seize the day, lads! Make your lives extraordinary!" was used in the hit movie, "Dead Poets Society", a film that explores the idea of "Carpe Diem" from the viewpoint of a classroom of young men at an all boys boarding school. It is said by Robin Williams' character, Professor Keating, in the hope that the students will learn to do what they want to do. The film explores the various ways in which the students seize the day and the consequences they face.