What were the differences between the Italian Renaissance and the Northern Renaissance?

Answer 1

The Renaissance, which had begun in 14th century Italy, spread like wild fire
through all the major centers of Europe. The term “Renaissance” means “rebirth.” In a narrow sense, this period marked the revival of Greek and Latin literature. In a wider sense, it marked a period of transition between the Middle Ages and the Modern Era. It was a period when a new humanistic spirit was abroad, replacing the God-centered orientation of the Middle Ages. The Renaissance was a time of adventure, enterprise, geographical discovery, great art and literature, and above all, it was a period of intellectual quickening.

In Italy, the men of the Renaissance made a cult of beauty and were generally more interested in the classical culture of ancient Greece and Rome than in theology. The Renaissance popes, for example, spent huge amounts of money in amassing great works of art and literature, and beautifying the Vatican.

But in the countries north of the Alps, the Renaissance took a different emphasis. This is seen in the work of the Biblical Humanists. Instead of being interested in the classical past of Greece and Rome, these Renaissance scholars were interested in the past of Christianity and their Judeo-Christian heritage. Like eager beavers, they dug into the Greek and Hebrew texts of the Bible, and the writings of the Church Fathers. In so doing, they furnished the Protestant Reformation with the historical background necessary to prove that the institutionalized Church of their day had departed from the simple faith and practice of New Testament Christians and early Church Fathers

Answer 2

Phoebhart gave a good answer. I'll just try to flesh it out a bit more.

As to the Italian Renaissance, think Michelangelo, Leonardo da Vinci, Botticelli--sumptuous, ravishing art, full of color and classical form. Think of writers like Petrarch and Ariosto--passionate, sweeping works, love poetry and grand epics. Think of mystical, spiritual philosophers like Marsilio Ficino or Giordano Bruno...

In contrast, the Northern Renaissance is typically characterized as being more somber, perhaps more scholarly. In art, we see the precise, careful portraits of Holbein (the younger) or the dark dream-like images of Bosch. In philosophy, we find religion--and in particular, the Reformation--playing a large role (the debates between Erasmus and Martin Luther, etc).

This is of course an extremely simplified view of things. There was a lot of reciprocal influence between the Italian and Northern Renaissances. And many important regions, such as France and Spain, don't quite fit comfortably into either category.