"Variation" refers to the differences or changes between things. It can describe the diverse ways in which something can be different or the fluctuations that occur within a certain thing or situation. Full definition
The significance is analyzed for the possible influence of variations of solar constant upon the energetic balance of the atmosphere. (realclimate.org)
Like anything in investing, there are lots of variations on how different investors employ the core and explore strategy. (cnbc.com)
If it does then the earth is self regulating in this regard with variation in climate more dependent on other factors. (judithcurry.com)