What do we mean by medieval peroiod?
The term "medieval period" generally refers to a time in the history of Europe. This was the time between the fall of the Roman Empire and the beginning of what is called The Renaissance. The dates usually give for this period are 5th century to 15 century CE (or AD).
Traditionally, this period was known as the "Middle Ages" or often the "Dark Ages." The second term was used because people used to say that Europe pretty much lost all its civilization during this time. The continent went back to lacking education and technology (and so Europeans could no longer build amazing roads like the Romans did, for example). Recently, historians have stopped using this term because they believe that it overstates things. They believe that the Middle Ages were not as uncivilized as the old view said.
Generally, the 'Medieval Period' was referred to as the Middle Ages which lasted from the 5th Century to the 15th Century. It was referred to as the Medieval Period by italian scholars back in the late 15th century. Since that time, historians conveniently used that name in order to refer to that specific time of European History.