The Renaissance was the period of time following the Middle Ages where a dramatic cultural shift began in Italy and spread across Europe. "Renaissance" means "rebirth," referring to the newfound flourish of culture, arts, and scholarship during this time period.
Humanism was an important ideal of the Renaissance which would later have a great impact in political revolutions and the ordering of new governments. Humanism emphasizes the human person in relation to the world, God, and government. This ideal was somewhat controversial at the time, because the Catholic Church-- the primary religion of Europe-- held that humanism was contrary to the teachings of predestination and God's power.
The Church had much to say against the cultural shifts of the Renaissance, especially where science was concerned. An interest in questioning and exploring the natural world (skepticism) was another driving force of Renaissance culture-- and a big insult to the Church! During this time there was an increased interest in anatomy and astronomy, and such inventions as the microscope and telescope reflect this interest in the sciences. A number of people were burned at the stake for speaking openly about scientific discoveries which went against Church teaching-- for example, heliocentrism.
During the Renaissance, people were also much more interested in individualism. This philosophy holds that individual people are responsible for their moral actions and life choices, rather than being solely governed by societal norms and pressures. In addition to individualism, scholarship was a high pursuit for the Renaissance person. People aspired to be knowledgeable on many subjects, from Classical philosophy, to anatomy, to foreign cultures, and the arts. Scholarship was considered a way to better one's individual life in a way that opened doors to better lives for the rest of their community.
Exploration, the arts, and trade were the means by which a person might really invest in bettering their community, and perhaps further themselves. A person who was knowledgeable in foreign cultures might be an excellent trader, acquiring spices and luxury goods in foreign lands. Skilled navigators explored to find new sea routes for trade and new lands where exotic goods, spices, and medicines might be acquired. Those who did well in travel and trade could stimulate the economy where they lived and become very wealthy themselves. So what does a Renaissance merchant do with all of his wealth? Commission some art for the betterment of his community and to get on the good side of the Church!
All around, the Renaissance was a time which idealized growth, knowledge, and the literal and metaphorical aesthetics of the Classic period.