Holland or the Netherlands?
Many people around the world call the country in northwestern Europe "Holland." But here is the surprising part: that is not really its name. The country's official name is the Kingdom of the Netherlands, usually shortened to the Netherlands. "Holland" is a nickname that has stuck for centuries, even though, strictly speaking, it is not correct.
What Holland Actually Is
So where does "Holland" come from? The Netherlands is divided into twelve provinces, which are a bit like states or regions. Two of those twelve provinces are named North Holland and South Holland. In other words, Holland is really just a part of the country, not the whole thing. Using "Holland" to mean the entire nation is a little like calling the whole United Kingdom "England" when England is only one part of it.
Why the Nickname Stuck
There is a historical reason this confusion runs so deep. The region of Holland was for a long time the richest and most powerful part of the country. Its great cities, including Amsterdam and Rotterdam, drove much of the nation's trade and wealth. When Dutch traders and sailors traveled the world centuries ago, they often spoke of "Holland," and foreigners naturally began using that name for the whole country. The nickname simply never went away.
Source
This article was written using information from Wikipedia.