Six Nobel prizes are awarded each year in the areas of:
The prizes are named after Alfred Nobel, the inventor of dynamite, who created the prizes in his will. He donated a good portion of his estate to fund the prizes, decided who would judge the winners of each award and also named the five prize categories (economics was added during the 1960s).
The Nobel Prizes are administered by the Nobel Foundation and are awarded in the fall after a rigorous selection process. The list of winners in the different categories (especially physics and chemistry) is like a Hall of Fame. For example, in physics the winners include Albert Einstein, Niels Bohr, Robert Millikan, Louis-Victor De Broglie, Werner Heisenberg and so on. It's a pretty prestigious list!
Today each prize is valued at over $1,000,000. The reason it is such a "big deal" is because of the size of the award and the fact that the award has been given since 1901-- long enough that everyone has heard about it.
Here are several interesting links: