A graduate school (sometimes shortened as grad school) is a school that 
awards advanced academic degrees (i.e. master's and doctoral degrees) 
with the general requirement that students must have earned a previous 
undergraduate (bachelor's) degree with a high grade point average.

A thesis or dissertation is a document submitted in support of candidature 
for an academic degree or professional qualification presenting the 
author's research and findings. In some contexts, the word "thesis" or 
a cognate is used for part of a bachelor's or master's course, while 
"dissertation" is normally applied to a doctorate, while in other contexts, 
the reverse is true. The term graduate thesis is sometimes used to refer 
to both master's theses and doctoral dissertations.

Degene die gaat promoveren wordt een promovendus genoemd. In principe wordt 
iemand die aan een proefschrift werkt een doctorandus genoemd ('hij die nog 
doctor moet worden'), maar in Nederland wordt de term promovendus al gebruikt 
vanaf de start van het onderzoeksproject, om verwarring met de (vandaag 
verouderde) term doctorandus te vermijden.