Is variation the same as variance? This is my first question on Cross Validated here, so please help me out even if it seems trivial :-) First of all, the question might be an outcome of language differences or perhaps me having real deficiencies in statistics. Nevertheless, here it is:
In population statistics, are variation and variance the same terms? If not, what is the difference between the two?
I know that variance is the square of standard deviation. I also know that it is a measure of how sparse the data is, and I know how to compute it. 
However, I've been following a Coursera.org course called "Model Thinking", and the lecturer clearly described variance but was constantly calling it variation. That got me confused a bit.
To be fair, he always talked about computing variation of some particular instance in a population.
Could someone make it clear to me if those are interchangeable, or perhaps I'm missing something?
 A: Here's a full wikipedia article discussing this topic: http://en.wikipedia.org/wiki/Statistical_dispersion
As described by others in the comments here, the short answer is: no, variation $\ne$ variance. Synonyms for "variation" are spread, dispersion, scatter and variability. It's just a way of talking about the behavior of the data in a general sense as either having a lot of density over a narrow interval (generally near the mean, but not necessarily if the distribution is skewed) or spread out over a wide range. Variance is a particular measure of variability, but others exist (and several are enumerated in the linked article).
A: @ttnphns is right, but since the info wasn't written as an answer, I'm going to attempt to steal the credit! :)
Variation may be understood best as a general term for a class of different concepts, of which variance $(\sigma^2)$ is only one. Levine and Roos (1997) also consider standard-deviation $(\sigma)$ a variation concept, among others. 
To demonstrate why the distinction might be important, compare also the coefficient-of-variation $(\frac\sigma\mu)$, and the mathematical concept, total variation, which has several definitions unto itself. Then there are all manners of qualitative variation, which are mentioned in the Wikipedia article @DavidMarx linked. These pages corroborate his answer BTW; statistical dispersion or variability are better synonyms for variation than variance, which is clearly not so synonymous.
BTW, here's a cool GIF of one kind of total variation: the length of the path on the $y$ axis that the red ball travels. 

Definitely not the same as variance!
Reference
Levine, J. H., & Roos, T. B. (1997). Description: Numbers for the variation. Introduction to data analysis: The rules of evidence (Volume I:074). Dartmouth College. Retrieved from http://www.dartmouth.edu/~mss/data%20analysis/Volume%20I%20pdf%20/074%20Description%20%20Numb%20for.pdf
