What is the difference between the Netherlands and Holand?

Answer 1

That's not exactly correct."Holland" is the county, which is now approx. the area of North and South Holland, which had the most contact through international trade during the time of the republic of the seven provinves. And after. So most foreigners who met Dutch were told they were from Holland. Which made that "Holland" became equivalent to the Netherlands.
Politically speaking the Netherlands were then a fairly loose confederation in which all members were pretty much independent but did work together through representatives at a council (in Den Hague). Holland was kind of the political centre but this had a lesser role in the spread of the name " Holland" than trade (anyway, in politics the correct name for the republic would have been used).

So, as a reply. Holland was a county which was part of the republic of the seven provinces. Most of this was united into "the Netherlands" (hence the plural "s"). Nowadays it's the two provinces which span approx. the area of the old county. "Holland" is still often used as the name for the coutnry but strictly speaking it's incorrect. Kind of like calling the UK "England".

Answer 2

They now both refer to the country. Historically, Holland was the political center of what is now the entire country (basically everything around the filled in polders in the middle of the country, from Amsterdam to Rotterdam and east almost to Utrecht; The Netherlands (which is the English word) has always referred to the entire country and is a newer term. Doesn't make a lot of difference unless you are a Frieslander (in the north and technically "not" Holland or a Limburger (in the south and ditto).

Answer 3

Indeed name Holland came from the the provincial name (Noord Holland, Zuid Holland). The Netherlands is the country in total. Because of the main trade centers (Amsterdam, Rotterdam) being located in those provinces (North and South Holland) .. it has been more famous aborad.