Question

What is the difference between ancient period and medieval period

Answer 1

These are all really nothing more than convenient labels for different periods. 

Ancient history is roughly from the earliest recorded events (with BC--"Before Christ"-- or BCE--"Before Common Era" --and a descending numbering system--300 BC is before 200 BC-- until approximately the birth of Jesus Christ, after which the numbering of years in the West is sequential, followed with AD or CE in some cases, to distinguish years with the same number) to around the fifth century of the AD ("Year of the Lord") or CE ("Common Era"). 

The medieval period is usually considered to be from the sixth to about the sixteenth century, and from the seventeenth on is pretty much modern history. 

The thing is, history is actually living and vibrant--and doesn't necessarily allow itself to be rigidly categorized. After all, the people who lived in the three periods mentioned all thought that THEY were in the MODERN period. 

I can just hear some Babylonian teen saying something like, 
"Dad, come on! This isn't the reign of Nebuchadnezzar! We're in the fifth year of Xerxes!" Or, perhaps in China, someone observing to his friend, "Oh, that went out with the Ch'in Dynasty!" 

Even the medieval period is sometimes broken down into the so-called Dark Ages, High Middle Ages, and Renaissance, so you see the labels can easily be blurred.