Renaissance: an intro
The word 'renaissance' is often used in two ways. The Renaissance is a period of time in European history, just as the Middle Ages are a period of time. But the word 'renaissance' is also used to point out what happened during this period in history.
The broadest definition of the Renaissance is that it stands for the cultural changes that took place in Europe from around 1450 up to 1650. To narrow this down, you can say that the Renaissance stands for a renewed interest in classical (ancient Greek and Roman) culture and literature. Most historians agree that these cultural changes first appeared in Italy in the late 14th and early 15th centuries and that they slowly spread all over Europe.

"The Creation of Adam". Part of the ceiling of the Sistine Chapel in the Vatican, painted by Michelangelo
When it comes to periods in history, the period of the Renaissance forms the bridge between the Middle Ages (500-1500) and the Modern Period (from 1700 onward). Whether the Renaissance is more medieval or more modern depends on how you look at it and on what you are looking at. On the one hand, you can still find a lot of medieval ideas and structures in the Renaissance. But, on the other hand, the Renaissance laid the groundwork for ideas and structures that were further developed in the modern period.