One difference is that in the Renaissance gunpowder was introduced. This ended the era of knighthood. Also, the "new world" was discovered in the Renaissance time period. Lastly, the compass was created. This helped explorers travel. In the Middle Ages the world was a thorough religious orientation. In the Renaissance the world began to change to a more secular world.
Renaissance also contributed more advances in science, art and literature. The development increased as a new "middle class" emerged. Religion was questioned after the Black death. Also, learning was more efficient to classical learning. Feudalism gave way to centralized forms of government. Economically, capitalism had began. Individualism, secularism, and rationalism were three principal features of the modern culture instead of a all "church society".
The Middle Ages were a time when no one questioned the Church and everything was centered around the Church. All art was made to glorify God. All music was made to glorify God. All literature was made to glorify God. And most wars were fought to glorify God including the Crusades. But around the time right after the Crusades people started to wonder why everything was about God. They were sick of it. God this God that God everything. When the Europeans were returning from fighting the Crusades the idea of humanism and materialism started to spread first starting in Italy and eventually spreading throughout Europe. Humanism was and is a movement that focused on human potential and achievements instead of God. Materialism was putting more value into material and tangible things rather than Godly and Holy things. These ideas made people more concerned with the here and now rather that what would happen tomorrow or more specifically whether they would get to heaven or not.
Along with the Renaissance came the Reformation(search Martin Luther) which was a time in which the Catholic Church cleaned up its ways and there was the birth of protestantism. During the Renaissance some of the worlds greatest thinkers, inventors, and artisans were born. Such as Leonardo da Vinci and Michaelangelo. It was a time of new ideas and great people. People like Leonardo were called Renaissance men. A Renaissance man was a person who was well rounded in all fields (science, art, history, the classics, sword fighting, dancing, singing, etc.)